Respuesta :
Answer:
-0.5
Step-by-step explanation:
7 - ? = 8
or
8 + ? = 7
since 7 < 8 we know the answer is negative, so instead we could write:
8 - ? = 7
by using mental math we know that the answer is 1, so:
8 - 1 = 7
7 - -1 = 8
(tip a double negative equals a positive so instead rewrite the equation as addition; 7 + 1 = 8)
Now we must remember that -1 = 2y so to solve for y we must divide each side by 2. -1/2 = 0.5 and 2y/2 = y so -0.5 = y. Have a great day! Hope this helps and GOOD LUCK!!!!!!!