400(1.07)=428
28(5)=140
140+400= 540.
$540 is your answer
15/7 or 2 1/7 (same number but the first one is an improper fraction and the other is a mixed fraction)
Answer:
(-2,3)
Step-by-step explanation:
Step 1. Isolate x for 3x + 5y = 9
3x + 5y - 5y = 9 - 5y
3x = 9 - 5y
3x/3 = 9/3 - 5y/3
x= (9-5y)/3
Step 2. Simplify
-3*((9-5y)/3) + 3y = 15
-3*((9-5y)/3) = 9 - 5y = -(-5 + 9) + 3y
-9+5y+3y
-9+8y = 15
Step 3 Isolate y for -9+8y=15
-9+8y+9=15+9
8y=24
8y/8 = 24/8
y=3
Step 4 Substitute y = 3
x = (9-5*3)/3
-(6/3) = (-2)
x = -2
