A would be the correct answer because the y variable only has a coefficient of 1. So we would solve for y, which would get us y=3x+5, then we would substitute the value in the second equation which would look like -4x+5(3x+5)=58. Hope this helpss. :)
Let number of hours needed to work = x
Multiply number of hours by rate: 15x
Add what you already have saved:
15x + 215
This needs to equal at least 800:
The equation becomes:
15x + 215 >= 800
Solve for x:
15x + 215 >= 800
Subtract 215 from both sides
15x >= 585
Divide both sides by 15
X >= 39
They have to work at least 39 hours.
Number 5 is 15.9 kilograms
And number 6 is 6 million cubic feet per minute
You just cross multiply
Radius= 33
Diameter = 66
Circumference = 207 yards
Area= 3,421 yards squared
Hope that helped :D