How do I solve these questions?
3 1/3 - 2 2/5=
2.75 + .003 + .158 =
7/20 is equal to ?
What is the value of the expression
2x2+ 3xy – 4y2
when x = 2 and y = - 4?
16x - 8 =
If 2x – 3(x + 4) = - 5, then x =
– 3(5 – 6) – 4(2 – 3) =
To solve these questions, you can follow these steps:
1. Question 1:
To subtract mixed numbers like 3 1/3 - 2 2/5, first, convert the mixed numbers to improper fractions. Then, find a common denominator and subtract the fractions. Finally, simplify the result (if necessary).
- Convert 3 1/3 to an improper fraction:
3 1/3 = (3 * 3 + 1)/3 = (9 + 1)/3 = 10/3
- Convert 2 2/5 to an improper fraction:
2 2/5 = (2 * 5 + 2)/5 = (10 + 2)/5 = 12/5
- Find a common denominator: In this case, the common denominator is 15 since both 3 and 5 go into it evenly.
- Subtract the fractions:
(10/3 - 12/5) = (50/15 - 36/15) = 14/15
- Simplify the fraction if necessary: Since 14/15 cannot be simplified further, the final result is 14/15.
2. Question 2:
To add decimals like 2.75 + .003 + .158, simply add the numbers together.
- Add the decimals:
2.75 + .003 + .158 = 2.911
- The sum of the decimals is 2.911.
3. Question 3:
To express the fraction 7/20, there are two approaches: as a decimal and as a simplified fraction.
- As a decimal: Divide the numerator (7) by the denominator (20) to get the decimal representation.
7/20 = 0.35
- As a simplified fraction: Simplify the fraction if necessary. In this case, 7/20 cannot be simplified further.
7/20 is already in its simplest form.
4. Question 4:
To evaluate the expression 2x^2 + 3xy - 4y^2 when x = 2 and y = -4, simply substitute the given values into the expression and perform the calculations.
- Substitute the values of x and y into the expression:
2(2)^2 + 3(2)(-4) - 4(-4)^2 = 2(4) + 3(-8) - 4(16) = 8 - 24 + 64 = 48
- The value of the expression is 48.
5. Question 5:
To solve the equation 16x - 8 = 0, isolate the variable x.
- Isolate x:
16x - 8 = 0
16x = 8
x = 8/16
x = 1/2
- The value of x that satisfies the equation is 1/2.
6. Question 6:
To evaluate the expression -3(5 - 6) - 4(2 - 3), follow the order of operations (PEMDAS/BODMAS).
- Evaluate within the parentheses:
-3(5 - 6) - 4(2 - 3) = -3(-1) - 4(-1)
- Perform the multiplication:
-3(-1) - 4(-1) = 3 + 4
- Add the results:
3 + 4 = 7
- The value of the expression is 7.
3 1/3 - 2 2/5=
3 1/3 = 2 4/3 = 2 20/15
2 2/5 = 2 9/15
2 20/15 - 2 9/15 = ?
2.75 + .003 + .158 = ?
7/20 = 0.35