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:
B
Step-by-step explanation:
She reads at 55 pages per hour for 4 hours so 55*4 = 220 pages so far. This means that she read 220 and had 330 left so 220 + 330 = 550 so the book is 550 pages. If she reads 55 pages per hour and there is a total of 550 pages, 550/55 = 10 hours to read the book.
You could actually find the compositions and thus have something to compare. You haven't shared the list of possible answer choices.
(f+g)(x) = 5x - 3 + x + 4 = 6x + 1
(f-g)(x) = 5x - 3 - x - 4 = 4x - 7
(f*g)(x) = (5x-3)((x+4) = 5x^2 + 20x - 3x - 12 = 5x^2 + 17x - 12
There are also the quotient (f/g)(x) and the compositions f(g(x)) and g(f(x)).
WRite them out.
Then you could arbitrarily select x values, such as 2, 10, etc., subst. them into each composition and determine which output is greatest.
