You are looking for a speed in miles per hour, so start by converting 90 minutes into hours.
90/60 = 1.5
90 minutes = 1.5 hours
speed = distance/time = (105 miles)/(1.5 hours) = 70 mph
Answer:
a=2.48
c=9.52
Step-by-step explanation:
a+c=12
4a+7.5c=72.5 Given
a+c=12
-4a-7.5c=-72.5 multiply the equation by negative 1
-3a-6.5c=-60.5 simplify
-3a=-60.5+6.5c add 6.5c to both sides
a=-20.17+2.17c divide it by 3
now you would take that equation and plug it into an equation you already have since you have something to plug in for a, the easiest one to do is a+c=12
(-20.17+2.17c)+c=12 plug in the equation
-20.17+3.17c=12 simplify by solving for c
3.17c=30.17 add 20.17 to both sides
c=9.52 divide both sides by 3.17
now since you have found c, you can plug it in to you equation to solve for a now (use the ones from the second step). I am using the equation a+c=12.
a+9.52=12 plug in the variable and solve for a
a=2.48 subtract 9.52 to both sides
a=2.48
c=9.52
Simplify
9x^3 - 4x + 10 + x^3 + 10x - 9
Collect like terms
(9x^3 + x^3) + (-4x + 10x) + (10 - 9)
Simplify
<u>10x^2 + 6x + 1</u>
Answer:
42
Step-by-step explanation:
3x^2 +5x
Let x=3
3(3)^2 +5(3)
3*9 +15
27+15
42
