math/algebra

please check my answers

Suppose that the temperature outside is dropping at a constant rate. At noon, the temperature is 70 F and it drops to 58 F at 5 p.m. How much did the temperature change each hour?
12/5=2.4 degrees per hour.

Evaluate the expression if a=-2, b=5,c=-4, and d=6:4b+5d-c/a


4b+5d-c/a =

4(5)+5(6)-(-4)/(-2)
4x5=20
5x6=30
-4/-2=2
answer= 20+30+2=52

Evaluate the expression if a=-2, b=5,c=-4, and d=6: 6^2-2bc+c^2

---> 5² - 2(5)(-4) + (-4)²
= 25 + 40 + 16
= 81

The simple interest I on a principle of P dollars at interest rate r for time t, in years, is given by I=Prt. Find the simple interest on a principle of $6000 at 3% for 2 years. (Hint: 3%=0.03)
Interest = 6000*.03*2

Simplify using the distributive property:7(4w-3)-25=
-21+25w+28w=
-21+3w
A triangle has sides 3x+7, 4x-9, and 5x+6. Find the expression that represents the perimeter.

=3x + 7+ 4x - 9+5x +6
=3x+4x+5x +7-9+6
=12x-3


Simplify, if possible: 6x^2y^3+9x^2y^3/3x^2y^2

  1. 👍
  2. 👎
  3. 👁
  1. The temperature one is correct. You may want to include a negative sign to indicate that the temperature is dropping.

    You made a sign mistake on the first evaluation. (You dropped one of your negative signs.)

    On the second evaluation, you changed "6^2" to "5^2" in your work.

    For the simple interest, you should multiply what you have to get a numerical answer in dollars.

    Your distributive property problem is quite wrong. The distributive property states for an expression a(b+c), the answer will be ab + ac. Try to apply that to your problem.

    On the perimeter, check 7-9+6. It's not -3.

    1. 👍
    2. 👎
  2. -x+2y=3
    3x+2y=-1

    1. 👍
    2. 👎

Respond to this Question

First Name

Your Response

Similar Questions

  1. calculus help thanks!

    The gas law for an ideal gas at absolute temperature T (in kelvins), pressure P (in atmospheres), and volume V (in liters) is PV = nRT, where n is the number of moles of the gas and R = 0.0821 is the gas constant. Suppose that, at

  2. 8th Grade Math

    The temperature in Toronto at noon during a winter day measured 4°C. The temperature started dropping 2° every hour. Which inequality can be used to find the number of hours, x, after which the temperature will measure below

  3. chemistry

    Determine the overall orders of the reactions to which the following rate laws apply: a. rate = k[NO2]^2 b. rate = k c. rate = k[H2][Br2]^1/2 d. rate = k[NO]^2[O2] I think the answers are: a. Second Order b. Zero Order c. First

  4. Calculus-Math

    The speed S of blood that is r centimeters from the center of an artery is given below, where C is a constant, R is the radius of the artery, and S is measured in centimeters per second. Suppose a drug is administered and the

  1. Physical Science

    So, please check my answers here: 1. Which example identifies a change in motion that produces acceleration? A) A speed skater moving at a constant speed on a straight track** B) A ball moving at constant speed around a circular

  2. physics

    This graph in the figure (Figure 1) shows how the temperature of an initially solid sample changes as time goes by when it is placed above a flame that delivers a constant heating power (that is, a fixed amount of energy input in

  3. algebra

    The temperature is dropping 1.5 degrees each hour after 6 hours the temperature is 38 degrees how t write this equation?

  4. College Algebra

    According to Newton's law of cooling, the rate at which an object cools is directly proportional to the difference in temperature between the object and the surrounding medium. The face of a household iron cools from 130° to

  1. math

    the temperature has been falling at a constant rate of 4 degrees F per hour.describe the temperature 4 hours ago

  2. Chemistry

    The first-order rate constant for the decomposition of N2O5, 2N2O5(g) --> 4NO2(g) + O2(g), at 70 degrees C is 6.82 x 10^-3 s^-1. Suppose we start with .0208 mol of N2O5(g) in a volume of 2.2 L. How many minutes will it take for

  3. calculus

    1. Estimating the Temperature of a Yam Suppose you put a yam in a hot oven, maintained at a constant temperature of 200C. As the yam picks up heat from the oven, its temperature rises.16 (a) Draw a possible graph of the

  4. Chemistry

    Given that the initial rate constant is 0.0190s−1 at an initial temperature of 22 ∘C , what would the rate constant be at a temperature of 190 ∘C for the same reaction described in Part A? Activation Energy 32.4kJ/mol

You can view more similar questions or ask a new question.