Answer:
a = 4, b = 8
Explanation:
Rewrite 5b=6a+16 and 9a=7b-20 vertically:
5b=6a+16
9a=7b-20
Let's use substitution. Solve the first equation for b:
6a + 16
b = --------------
5
Substitute this result into the second equation:
9a = 7(b) + 16, or
6a + 16
9a = 7*-------------- - 20
5
Eliminate the fraction by multiplying all three terms by 5:
45a = 7(6a + 16) - 100, or
3a = 112 - 100, or:
3a = 12, which leads to a = 4.
Find b by subbing 4 for a in either of the given equations:
5b = 6(4) + 16, or
5b = 40, leading to b = 8
The solution is a = 4, b = 8