Question

How do I solve this please help!​

Answer 1

Answer:

9 x + 8 y = 10   (I)

y = -4x + 7        (II)

One way is to rewrite the second as

4x + y = 7

Now multiply this equation by 8

32 x + 8 y = 56

9 x + 8 y = 10        and now subtract the equations

23 x = 46     this gives x as 2

From equation (II)  y = -4 (2) + 7  = -1

So our values are (2, -1)

Check:

(I) 9 x + 8 y = 10         9 * 2 - 8 = 10

(II)  4 x + y = 7       or 4 * 2 - 1 = 7

Or you can substitute equation (II) directly into equation (I)