Question

Solve each system by elimination.

a. 2x + 3y = 33
y= 1/4x

Answer 1

elimination would be a poor choice for this one , why not use substitution ?

y = (1/4)x into the first .....

2x + 3(1/4)x = 33
times 4
8x + 3x = 132
11x = 132
x = 12
then y = (1/4)(12) = 3

x=12 , y = 3

by elimination:
work on the 2nd
4y = x
x - 4y = 0
times 2
2x - 8y = 0
so now:

2x + 3y = 33
2x - 8y = 0
subtract them:
11y = 33
y = 3
sub into x - 4y = 0
x - 12 = 0
x = 12

so x = 12, y = 3
same as above.