7-3/4(-8x+20)

Question

seven and three fourths times negative eight plus twenty

Answer 1

Hi Cheri,

I believe you are trying to solve for 7 - (3/4)(-8x+20) = 7 + (-3/4)(-8x+20)

First, you want to use the distributive property by multiplying the -3/4 by everything that is inside the parenthesis. So,

(-3/4)(-8x+20) = (-3/4)(-8x) + (-3/4)(20) = (24x/4) + (-60/4) = (6x) + (-15) = 6x - 15

The equation now becomes:    7 + 6x - 15

Adding the like terms, you end up at the following:      6x - 8

Answer 2

The way this sort of equation (i.e. one value multiplied by two values added together within parentheses) is you multiply the value outside the parentheses by each value inside, separately, and then add them together.  As a simple example to demonstrate how it works, we'll use 4(2+9).  4x2=8 and 4x9=36, and 8+36=44, which is the same as 4x11.

Now to your question: 7-3/4 times -8x=-62x, and 7-3/4 times 20=155.  Adding the two values together gets you -62x+155.

However, I notice that in your non-numeral version of the question, you don't have x.  So, if that's the case, it'd simply be -62+155=93