Step-by-step explanation:
2(x-3)=5(x-3)+10
=> 2x - 6 = 5x - 15 + 10
=> -6 + 15 -10 = 5x - 2x
=> 5x -2x = 15 - 6 - 10
=> 3x = 15 - 16
=> 3x = -1

First, take half of the coefficient of 18x then square it.
18 / 2 = 9
9^2 = 81
So, D. 81 is the answer.
Eight *(a number) plus 5*(another number) is -13.
translates to:
8(x) + 5(y) = -13
The sum of (the number) and (the other number) is 1.
translates to:
(x) + (y) = 1
We have a system of two equations involving two unknowns: x and y.

We can easily solve the system using Substitution or Elimination. Let's use Elimination this time.
We'll multiply the second equation by -8 so that the x's match up.

When we add the equations together, the x's will fall out of the equation, summing to zero. The 5y and -8y will sum to -3y and the right hand side will sum to -21.

Divide by -3,

Plug back into one of your original equations to find the value of x,

Subtract 7,
They are both the same. There are 60 seconds in one minute, so 60*3 is 180. Since 180=180, they are equal.
:)