Answer 30 both parts i need ! you so much! best answer gets brainliest!

Let the variable s represent the amount Trey saved before mowing lawns.

Trey earns s dollars. Then he earns an additional $40. So far, he earns (s+40).
Then this amount is doubled: 2(s+40)
At the end, he has $234. So the equation is
2(s+40) = 234
2s + 80 = 234
2s = 154
s = 77

An arithmetic approach (solving using addition) could have the equation as
(s+40) + (s+40) = 234
s + 40 + s + 40 = 234
2s = 154
s = 77

answer:

a system of linear equations contains two or more equations e.g. y=0.5x+2 and y=x-2. the solution of such a system is the ordered pair that is a solution to both equations. to solve a system of linear equations graphically we graph both equations in the same coordinate system.

step-by-step explanation: your welcome owo