Answer is <span>C. 9x-2y=-40
hope that helps
because y = 9/2x +20 then 2y = 9x + 40 so 9x -2y = -40
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Let x = amount of 45% antifreezeLet y = amount of 70% antifreeze EQUATION 1: x + y = 150 (total of 150 gallons mixed) EQUATION 2: .45x + .75y = .55(x + y) Simplify and solve the system of equations Multiply second equation by 100 on both sides to remove the decimals 45x + 75y = 55(x + y) Combine like terms 45x + 75y = 55x + 55y 45x - 55x + 75y - 55y = 0 -10x + 20y = 0 Now we have the following system of equations: x + y = 150 -10x + 20y = 0 Multiply the first equation by -10 to get opposite coefficients for x; add the equations to eliminate x 10x + 10y = 1500 -10x + 20y = 0 ------------------------------ 30y = 1500 Solve for y 30y = 1500 y = 50 Since the total mixed gallons is 150, x = 150 - 50 = 100 So we need 100 gallons of the 45% antifreeze and 50 gallons of the 70% antifreeze
Bob works at a factory.
He makes $120 a day and Bob needs to make a certain amount of money to pay his bills at the end of three months. Bob has to pay $8675 for his bills. If Bob worked 75 days, does he have enough to pay his bills?
(answer)
Yes.
(work)
120 x 75 = 9000
9000-8675
I hope this helped!
Answer:
To express percentages in decimal form, you start with the decimal on the right side of the percentage, then you bring the decimal two places to the left. So for example, for 5% it it 5.. when you bring the decimal two places to the left it becomes .05
We start with $371.93 then we multiply each percentage successively to this number
we work backwards
so we start with 5%
$371.93= .95 x X
X=$391.51
Then we take X and do the same process for 10%
$391.51= .90 x Y
Y = $435.01
again we take Y and do the same process for 25%
$435.01= .75 x Z
Z = $580.01
so the original price is $580.01
to find the total percent discount you take the total discounted price ($371.93) divided by the original price ($580.01) then you have 1 subtracted by the number. Finally, you multiply the number by 100 to change it to a percentage
so it's $371.93/$580.01 which = .64125
1 - 64125 = .35875 x 100= 35.88%
so your total percent discount is 35.88%
Hope this helps
