I agree with what that person told you. The expression -2(x+10) is equivalent to -2x-20
Multiply the outer -2 with the inner x to get -2 times x = -2x
Multiply the outer -2 with the inner term 10 to get -2 times 10 = -20
So overall, -2(x+10) = -2x-20
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So that's how we're able to go from this
to this
The only thing that changes is the left side. The inequality sign will not flip. It only flips if we multiply both sides by a negative number.
Answer:
x=1
Step-by-step explanation:
-2x + 4 = 5 - 3x
Add 3x to each side
-2x+3x + 4 = 5 - 3x+3x
x +4 =5
Subtract 4 from each side
x+4-4 =5-4
x =1
The answer is 10 as the diameter because it says to estimate pi as 3. Since we know the circumference is 30 we can reverse it to find the diameter, since Circumference is pi time diameter.