Math
posted by Gilda .
Solve the pairs of simultaneous equations by the substitution method.
5x9y=17
3x8y=5

(poor method for this particular question, but ...)
solve the second for x, (I look for the smallest coefficient)
3x = 5+8y
x = (5+8y)/3
sub into the first
5(5+8y)/3  9y = 17
multiply by 3 to eliminate fractions
5(5+8y)  27y = 51
25 + 40y  27y = 51
13y = 26
y = 2
then x = (5+16)/3 = 7