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
Answer:
(61/7, -47/7)
Step-by-step explanation:
Given: y=2/7 -7
y=-x+2
Rewrite the top equation ( y=2/7 -7
y = -47/7
y = -x + 2
Because both equations are equal to y, we can rewrite it again.
-47/7 = -x + 2
Add x to both sides
x + (-47/7) = 2
Add 47/7 to both sides.
x = 47/7 + 2/1
x = 61/7
As stated in the beginning, y is equal to -47/7
Hope you understand!
Answer:
1. C. Yes, because a sum of cubes can be factored
2a. false
2b. false
2c. true
2d. false (based on what is written in the equation; refer to step-by-step)
Step-by-step explanation:
1. Both 3 and 8 can be cubed, which is why x^3+8 can be factored (x+2)(x^2-2x+4)
2a. a^2-b^2 can be factored by the perfect square rule, so it should be (a-b)^2
2b. both terms are perfect squares, so you can factor, making it (a+b)(a-b)
2c. You can factor using the perfect square rule, making it (a+b)^2
2d. Most of what is in the equation is true, yet the correct solution would be (a-b)(a^2+ab+b^2)
Answer: speed is 540 km/h
Step-by-step explanation: Lets mark speed as v.
Because distenace is same, you can mark 6 h · 900 km/h = 10 h · v
and v = 5400 km / 10 h = 540 km/h.
Or using inverse proportions : 10 h / 6 h = v / 900 km/h .
Before multiplying you turn lastproportion around :
10 h / 6 h = 600 km/ h / v ,which gives 10 v = 6 · 900 km/h
and result is same
7.5 gallons. (5x60)/40 5x60 being the equation to find the total miles driven
