Question

How to solve -3x+8y=-18. (the bottom) 0=-10y-5x+30 using elimination?

Answer 1

-3x+8y=-18
0=-10y-5x+30

First move the 30 to the other side of the equal sign so you have the problum
-3x+8y=-18
-5x-10y=-30

Now times the top problum by 5 and the bottom one by 3 to get the new problum
-15x+40y=-90
-15x-30y=90

Now that you have a commen number in both problums you would subtract both of the problums.
-70y=180

Now that you have that divide the -70 on both sides.
y=2.57

Now you would substitute the y for the 2.57 in one of the problums.
-15x-30(2.57)=90

Times the -30 with the 2.57.
-15x-77=90

Now subtract the -77 on both sides.
-15x=13

Now divide the -15 on both sides to get your answer for x.
x=.86

Now thats your answers
y=2.57
x=.86
(.86,2.57)