Answer:
40 mph
Step-by-step explanation:
If the speed increased by 20%, now the speed is 120% of the original speed.
48 mph is 120%, so dividing by 6 will get 8 which is 20%.
If 8 is 20%, you can multiply it by 5 to get 40, which is 100%. This means 40 mph is the original speed.
Hope this helps!
We have 55% and 80% antifreeze. We need 90 gallons of 75%.
F - 55% and E - 80%
A) F + E = 90
B) .55 F + .80 E = 67.50 (which is .75 * 90) Multiplying A) by -.55
A) -.55 F -.55 E = -49.50 (which is -.55 * 90) then adding A) & B)
.25 E = 18
E = 72 gallons of 80% and
F = 18 gallons of 55%
********* DOUBLE CHECK ******************
72 * .80 = 57.60 and 18 * .55 = 9.90
57.60 + 9.90 = 67.50 gallons of antifreeze and we have 90 total gallons
(67.50 / 90) * 100 = 75% correct!
Source: 1728.com/mixture.htm
Answer:
678.74
that might be the question since I don't really understand what it says really
Answer:
C) x2 + x = 306
Step-by-step explanation:
x2 + x = 306
x2 + x - 306 = 0
x2 + 18x - 17x + 18 * (-17) = 0
x ( x + 18) - 17 (x +18) =0
(x + 18) (x - 17 ) = 0
x = -18 or 17
