Answer:
45, 36
Step-by-step explanation:
let x y minutes be the time for pipes to fill the tank, let n be the water needed to fill the tank.
x-y=9
(n/x)*20+(n/y)*20=n
n is removed by dividing the 2nd equation by n
here u get:
(1/x+1/y)*20=1
you sub x=9+y into the above equation
1/y+1/(9+y)=1/20
((9+y)+(y))*20=(9+y)(y)
180+40y=9y+y2
y2-31y-180=0
then use the quadratic formula and u will find y=36 or -5
-5 is rejected because it is negative
x=36+9=45
therefore it is 36 mins and 45 mins
it would be car d because of what the time was on the chart (i did the test and it was correct)
Answer:
3
Step-by-step explanation:
Answer:
Step-by-step explanation:
Ans:A.
6×5÷2×11=165
Answer:
see explanation
Step-by-step explanation:
Given
f(x) = ax + b
x = 2 → f(x) = 1 and x = - 1 → f(x) = - 5 ( from the table )
Substitute these values into f(x) = ax + b, that is
2a + b = 1 → (1)
- a + b = - 5 → (2)
Subtract (2) from (1) term by term to eliminate b
3a = 6 ( divide both sides by 3 )
a = 2
Substitute a = 2 into (2) and evaluate for b
- 2 + b = - 5 ( add 2 to both sides )
b = - 3
(b)
When x maps onto itself then
ax + b = x, that is
2x - 3 = x ( subtract x from both sides )
x - 3 = 0 ( add 3 to both sides )
x = 3
Thus a = 2, b = - 3 and x = 3
