Answer:
<em>102°</em>
Step-by-step explanation:
(3x - 12)° + (2x + 2)° = 180°
5x - 10 = 180 ⇒ x = 38
m∠A = (3x - 12)°
<em>m∠A</em> = (3×38 - 12)° = <em>102°</em>
Check the discriminant (always a good idea).
b^2 - 4ac
b = -19
c = -15
a = 10
(-19)^2 - 4(10)(-15)
361 + 600
961
Yes it can be factored, but if you like, you could use the quadratic formula.
x = [- (-19) +/- sqrt(961)]/(2 * 10)
x = [19 +/- 31 ] / 20
x = (19 + 31/20
x = (50)/20
x = 5/2
x = [19 - 31] / 20
x = [- 12]/20
x = -3/5
Getting the factors is a little tricky.
(x - 5/2)(x + 3/5) = 0
The first factor is found by putting
x - 5/2 in that form and multiplying through by 2
1/2 (2x - 5) The 1/2 comes from multiplying by 2.
The second factor is
1/5 (5x + 3)
So the equation will look like
1/2(2x - 5)1/5(5x + 3) = 0 If you multiply by 2 you get
(2x - 5)1/5(5x + 3) = 0 and now multiply by 5 you get
(2x - 5) (5x + 3)
Check
2x*5x - 25x + 6x - 15
10x^2 - 19x - 15 = 0
So everything works out.
Answer:
10 spiders and 12 ants
Step-by-step explanation:
You need to create two equations
s = # of spiders
a = # of ants
s + a = 22 heads
since each spider and ant has one head
8s + 6a = 152 legs
since every spider has 8 legs and every ant has 6
s + a = 22 can be turned into s = 22 - a
now use substitution
8(22 - a) + 6a = 152
176 - 8a + 6a = 152
176 - 2a = 152
24 = 2a
a = 12
now that you have the number of ants you can solve for the number of spiders
s + a = 22
s + 12 = 22
s = 10
Answer:
-1/3
Step-by-step explanation:
