Answer:
(5,7.5) (12,18) (18,27)
Step-by-step explanation:
It costs $1.50 per cupcake.
y = 1.5x, where x is the amount of cupcakes and y is the amount of money in dollars.
7.5 = 1.5 times 5
18 = 1.5 times 12
27 = 1.5 times 18
Easiest way is if you substitute each point (x,y) into each set of equations and both points work for both equations in the system of equations, then it is the correct answer
Otherwise substitute one equation for y in the other equation:
2x + 6 = x^2 + 5x + 6
-2x - 6. -2x -6
0 = x^2 + 3x. Factor
0 = x (x + 3)
Solve: x = 0. x + 3 = 0. ——> x = -3. Substitute into one original equation to get y value for
y = 2x + 6.
y = 2(0) + 6. y = 2(-3) + 6
y = 6. y = -6 + 6 —-> y = 0
(0 , 6) And. (-3 , 0)
First expand the equation.
-5e+5+6e = -17
Next, combine the like terms.
e+5 = -17
e = -22
Answer:
12.1 cm
Step-by-step explanation:
Using the law of sines, we can find angle C. Then from the sum of angles, we can find angle B. The law of sines again will tell us the length AC.
sin(C)/c = sin(A)/a
C = arcsin((c/a)sin(A)) = arcsin(8.2/13.5·sin(81°)) ≈ 36.86°
Then angle B is ...
B = 180° -A -C = 180° -81° -36.86° = 62.14°
and side b is ...
b/sin(B) = a/sin(A)
b = a·sin(B)/sin(A) = 13.5·sin(62.14°)/sin(81°) ≈ 12.0835
The length of AC is about 12.1 cm.
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<em>Comment on the solution</em>
The problem can also be solved using the law of cosines. The equation is ...
13.5² = 8.2² +b² -2·8.2·b·cos(81°)
This is a quadratic in b. Its solution can be found using the quadratic formula or by completing the square.
b = 8.2·cos(81°) +√(13.5² -8.2² +(8.2·cos(81°))²)
b = 8.2·cos(81°) +√(13.5² -(8.2·sin(81°))²) . . . . . simplified a bit
