Here, I'll do the first one for you.
When they are talking about a number, use "x".
Since it says twice a number, you say 2x. Or 3x for three times the number
2x+12=3x-31
Then use algebra to find x. Get the numbers on one side and all the x's on the other.
2x+12+31=3x-31+31
2x+43-2x=3x-2x
x=43
Now do the rest on your own!
Circumference is found with the formula
c = pi × d
d is diameter and we will use 3.14 for pi.
The diameter is the measure across the center of the circle. In the first problem, you are given the radius, so we have to multiply by 2 to get the diameter. Then we can use the formula.
12.4 in × 2 = 24.8 in (that's the diameter)
c = pi × D
c = 3.14 × 24.8
c = 77.872 inches
circumference is 77.872 inches.
Try the other problems on your own. They are just like this one. Just make sure they are giving you the diameter and not the radius. Post if you have problems.
Answer:
11.7
Step-by-step explanation:
multiply RS by the scale factor to get R'S'
Answer:
x² + 18x +81
x² - 14x +49
4x²- 4x - 1
Step-by-step explanation:
multiply the x in the first parentheses by x and 9 in the other parentheses and
multiply the 9 in the first parentheses by x and 9 in the other parentheses and add all together
(x+9)(x+9)
x² + 9x + 9x + 81
x² + 18x +81
multiply the x in the first parentheses by x and -7 in the other parentheses and multiply the -7 in the first parentheses by x and -7 in the other parentheses and add all together
(x-7)(x-7)
x² -7x - 7x +49
x² - 14x +49
(2x-1)² is the same as (2x-1)(2x-1)
multiply the 2x in the first parentheses by 2x and -1 in the other parentheses and multiply the -1 in the first parentheses by 2x and -1 in the other parentheses and add all together
(2x-1)(2x-1)
4x²-2x-2x+1
4x²- 4x - 1
