Thursday
September 18, 2014

Homework Help: Algebra

Posted by Tamir on Friday, June 11, 2010 at 10:19pm.

Can someone check my work for the following? I am supposed to use the five-step method to solve & check, but I don't know what that is. Anyway

1. One-third of a number is 5 less than half of the same number. What is the number?

My answer:
1/3x = 1/2x - 5
6(1/3x) = 6(1/2x) - 6( 5)
2x =3x - 30
2x - 2x = 3x - 30 - 2x
0 = x - 30
0 + 30 = x - 30 + 30
30 = x

x = 30

And to check:
1/3x = 1/2x - 5
1/3(30) = 1/2(30) - 5
30 / 3 = 30 / 2 - 5
10 = 15 - 5
10 = 10

2. The sum of a number and its reciprocal is 10/3. What is the number?

My Ans:
x+1/x= 10/3
(x^2+1)/x= 10/3
3 ( x^2+1)= 10 x
3x^2+3= 10x
3x^2-10x+3= 0
( 3x-1) ( x-3) = 0
3x-1= 0
x= 1/3
x-3= 0
x= 3

Check:
x+1/x= 10/3
3 + 1/3= 10/3
(9+1)/3= 10/3
10/3= 10/3

3. An investment of $1500 paid interest of $45 during a certain period. How much interest would an investment of $2000 invested at the same rate for the same length of time pay?

My Ans:
45/1,500=X/2,000
1,500X=45*2,000
1,500X=90,000
X=90,000/1,500
X=$60

Check:
45/1,500=60/2,000
90,000=90,000


4. In baseball a player's batting average is the ratio of hits to the number of times he or she has batted. Thus, if the player has an average of .3000, it means he or she got 300 hits in 1000 at bats. In order to have an average of .300, how many hits would the batter have to get in 400 times at bat?

My Ans:
batting average=(hits)/(times batted)
your batting average =.300
times batted=400
hits=x


.300 = x/400
(400).(.300)= 400x/400
120 = x

Check:
.300 = 120/400
.300 = 300

Thanks in advance everyone.

Answer this Question

First Name:
School Subject:
Answer:

Related Questions

Algebra - Hello, can someone tell me if I got the following solve and check work...
Algebra - Hello, can someone help me solve and check the following 1) x - 8 = 20...
Algebra 2 - can someone show me how to do it step by step please! Use a graph ...
Algebra 1--Step-by-Step - Can someone show me how to solve these step-by-step? ...
Algebra - Use substitution method to solve the linear system. Can someone please...
Algebra2 - i was wondering if someone could check the answer i got for this math...
math/algebra - solve each of the following systems by substitution. 16) 5x -2y...
Math Algebra - Resolve(17x+14x + 9) (-13x +6x - 12) 30xsquared+20x+21 I'll ...
help...solving a polynomial....algebra - solve this please....help me....12x(...
calc check: euler's method - Given the differential equation: dy/dx = y(1+x), y(...

Search
Members