math
posted by
lisa on
.
x5y=21
9y8x=44
substitution method

math 
Ms. Sue,
x5y=21
9y8x=44
x = 5y  21
9y  8(5y  21) = 44
9y  40y + 168 = 44
31y = 44  168
31y = 124
y = 4
Take it from there.

math 
Kuai,
x = 5y 21
9y8(5y21) = 44
9y 40y +168 = 44
31y + 168 = 44
31y + 168 168 = 44 168
31y = 124
y = 4
x = 5(4)21 = 1
(1, 4)