Hi!
So we have to make a system of equations here.
Let sibling 1 be O and sibling 2 be Y (for older and younger)
So:
O + Y = 64
O = 64 - Y
(Either one works)
The older sibling is 6 years older.
O = Y + 6
Make everything in terms of Y.
64 - Y = Y + 6
Same to both:
58 = 2y
2y = 58
Divide by 2 on both sides:
y = 29
Since the older sibling is 6 years older:
29 + 6 = 35
Y = 29
O = 35
Let me know if you have any questions.
<u>Solution-</u>
Zachary purchased a computer for 1800 on a payment plan. (Initial Money)
3 months after he bought the computer, his balance was 1350. (Money after 3 months)
Total money paid in 3 months = 1800-1350 = 450
Money paid per month = 450/3 = 150
5 months after he bought the computer, his balance was 1050.
Total spent = 1800-1050 = 750 = (5× 150)
So the equation that models the balance b after m months,
b = 1800 - m(150)
∴ Here, the slope signifies the constant monthly deduction of $150.
The answer is 21 because 189 divided by 9 is 21