Answer:
x = $0.85 per pound = 19.85 pounds
y = $2.70 per pound = 1.14 pounds
Step-by-step explanation:
Let
x = $0.85 per pound
y = $2.70 per pound
x + y = 21 (1)
0.85x + 2.70y = 19.95 (2)
From (1)
x = 21 - y
Substitute x = 21 - y into (2)
0.85x + 2.70y = 19.95 (2)
0.85(21 - y) + 2.70y = 19.95
17.85 - 0.85y + 2.70y = 19.95
- 0.85y + 2.70y = 19.95 - 17.85
1.85y = 2.1
y = 2.1 / 1.85
y = 1.14
Substitute y = 1.14 into (2)
0.85x + 2.70y = 19.95
0.85x + 2.70(1.14) = 19.95
0.85x + 3.078 = 19.95
0.85x = 19.95 - 3.078
0.85x = 16.872
x = 16.872 / 0.85
x = 19.85
x = $0.85 per pound = 19.85 pounds
y = $2.70 per pound = 1.14 pounds
The steps for dividing fractions are:
Keep
Flip
Change
As in, keep the first fraction the same (we can write 7 as 7/1 to make it a fraction), flip the second fraction upside down, and then change the division symbol to a multiplication symbol. This gives you:
7/1 × 5/6
And to multiply fractions, you multiply across, which means that you do (7 × 5 = 35)/(1 × 6 = 6). Your answer, therefore, is 35/6, or, as a mixed number, 5 5/6. I hope this helps!
a = hours worked by the first mechanic
b = hours worked by the second mechanic.
since the first mechanic charges $55 per hour, then for "a" hours that'd be a total of 55*a or 55a, likewise, for the second mechanic that'd be a total charge of 80*b or 80b.
we know all hours combined are 15, so then a + b = 15.
we also know that all charges combined are $950, so 55a + 80b = 950.
