Answer:
24
Step-by-step explanation:
The sum of the their ages is 72. 48 divided by 2 is 24. 48 plus 24 is 72
Answer:
A
Step-by-step explanation:
Both angles together are supplementary, or they add up to 180 degrees.
(3x+12)+x=180 degrees
You haven't listed the possible solutions, so in the immediate present I can help only by suggesting that you try solving this system and checking your own answers thru subst. into the given equations.
Please be sure to use "^" to indicate exponentiation, as shown below:
<span>4x2 + 9y2 = 72 should be 4x^2 + 9y^2 = 72 (this is the eq'n of an ellipse)
x - y2 = -1 should be x - y^2 = -1 (this is the equation of a parabola)
We must eliminate either x or y. I will solve the 2nd equation for y^2 and subst. the result into the first eq'n.:
y^2 = x+1. Subst. this into the first equation,
</span>4x^2 + 9y^2 = 72 becomes 4x^2 + 9(x+1) = 72.
Expanding, 4x^2 + 9x + 9 = 72, or 4x^2 + 9x - 63 = 0
We must solve this quadratic equation to obtain the x-coordinates of possible solutions of the original system of equations.
-9 plus or minus 33
After some work, we get x = ------------------------------
8
So x = 24/8 = 3, or x = -42/8 = -5 1/4 or -21/4
Check out x=3. We already have the relationship y^2 = x+1. If x = 3, then y^2 = 3+1 = 4, and y is plus or minus 2.
Two possible solutions of the original set of equations are thus (3,2) and (3,-2). You MUST check both solutions thru substitution to determine whether they satisfy the original equations or not.
Answer:
B
Step-by-step explanation:
Given y and x vary directly then the equation relating them is
y = kx ← k is the constant of variation
To find k use the condition y = 27 when x = 4 , then
27 = 4k ( divide both sides by 4 )
= 6.75 = k
y = 6.75x ← equation of variation
When x = 12 , then
y = 6.75 × 12 = 81
If you let x be the number to get 8 more you add so it would be x+8
