Question 58181
to solve we isolate y to solve for x

0.5x-0.3y=7
move the x to the side
-.3y=7-.5x
0.3Y=-7+0.5X
divide both sides to isolate y

Y=(-7/.3)+(0.5/0.3)X

now you substitute in the new equation for y in the second equation


0.3x-0.4((-7/.3)+(0.5/0.3)X)=2

expand the terms into the brackets and simplify the term

0.3X+(28/3)+-(2/3)x=2
11/30X+(28/3)=2
subtract (28/3) from each side
11/30X=-22/3
divide out 11/30 from each side to isolate x
x=-20

now substitute x into the equation to find y

0.5(-20)-0.3y=7
-10-.3Y=7
add 10 to each side
-.3Y=-3
divide by .3
y=10

so x is -20 and y is 10