7. 4x+y=8 ----- first equation
(+)
-3x-y=0
_______
x = 8 ---- second equation
substitude second equation into first equation
4(8) + y = 8
32 + y = 8
y = 24
8. 2x+5y=20 ---- first equation
(-)
2x-5y =3
________
10y = 17
y = 17/10 ---- second equation
substitude second equation into first equation
2x + 5(17/10) = 20
2x + 17/2 = 20
4x + 17 = 40
4x = 23
x = 23/4
9. 3x+2y=-10 (×2) ---- first equation
2x-5y=3 (×3)
6x + 4y = - 20
(-)
6x - 15y = 9
___________
19y = - 29
y = - 29/19 ---- second equation
substitude second equation into first equation
3x + 2(-29/19) = - 10
3x - 58/19 = - 10
3x = - 132/19
x = - 44/19
Answer:
630 ml
Step-by-step explanation:
1 glass contains 180 ml juice
7/2 glasses contains = 180 × 7/2 = 630 ml
Answer:
$150
Step-by-step explanation:
First use a proportion to find the answer:
40/100=60/x
Now we solve for x
60*100=6,000
6,000 divided by 40= 150
x=150
Therefore the answer is $150
Equation 1 (rent): y = 5x
Equation 2 (buy): y = 3x + 28
5x = 3x + 28 <em> substituted "y" with "5x" into Equation 2</em>
2x = 28 <em>subtracted 2x from both sides</em>
x = 14 <em>divided both sides by 2</em>
You will break even on the 14th time. You will save money by renting if you go 15 times.
Answer: 15 times
17.09 has 2 decimal places, so we put the decimal digits of 17.09, 09, over 1 followed by the number of zeroes equal to the number of decimal places, 2: 09 = 09/100. We add 17 as 1700/100 and get: 17.09 as decimal fraction = 1709/100