Jonas used linear combination to solve the system of equations shown. he did so by multiplying the first equation by –3 and the second equation by another number to eliminate the x-terms. what number did jonas multiply the second equation by?
4 x - 6y = 2
0.5x + 0.1y = 8.5

let soccer = x and golf = y

part a

1st equation: x + y = 125

2nd equation: x = y +45

part b

replace x in the 1st equation with the 2nd one:

y + 45 + y = 125

simplify:

2y + 45 = 125

subtract 45 from each side:

2y = 80

divide both sides by 2:

y = 80/2

y = 40

she plays golf for 40 minutes.

part c

no because she plays soccer for 45 minutes longer than golf 40 +45 =   85 minutes, not 80 minutes.