If 5y = 6x + 16 and 9x = 7y - 20, what is the value of 3x - 2y?

16

Step-by-step explanation:

5y=6x+16 ... (I) and 9x=7y-20 ... (ii)

Using substitution method:

Multiply equation ii by 5

45x=35y-100

Substitute (I) into ii

45x=7 * 5y - 20

45x=7 (6x+16)

45x=42x+112

45x-42x=112

3x=112 ...

5y=6x+16

5y=2*3x+16

5y=2*112+16

5y=224+16

5y=240

Divide both sides by 5

y=48

3x-2y

112-2*48

112-96

16