Answer:
26°
Step-by-step explanation:
AC=tan 64
BC=x=sec 64
Using sine rule
(Sin 64)/tan 64 = (sin BAC)/sec 64
Cos 64 = (sin BAC)(cos 64)
Sin BAC= 1
BAC=90
ACB+ 64+90=180
ACB= 26°
Answer:
A
Step-by-step explanation I counted the numbers.
<span>Simplifying:
2x2 + -8x + -90 = 0
Reorder the terms:
-90 + -8x + 2x2 = 0
Solving
-90 + -8x + 2x2 = 0
Solving for variable 'x'.
Factor out the Greatest Common Factor (GCF), '2'.
2(-45 + -4x + x2) = 0
Factor a trinomial.
2((-5 + -1x)(9 + -1x)) = 0
Ignore the factor 2.
Subproblem 1:
Set the factor '(-5 + -1x)' equal to zero and attempt to solve:
Simplifying
-5 + -1x = 0
Solving
-5 + -1x = 0
Move all terms containing x to the left, all other terms to the right.
Add '5' to each side of the equation.
-5 + 5 + -1x = 0 + 5
Combine like terms:
-5 + 5 = 0
0 + -1x = 0 + 5
-1x = 0 + 5
Combine like terms:
0 + 5 = 5
-1x = 5
Divide each side by '-1'.
x = -5
Simplifying
x = -5
Subproblem 2:
Set the factor '(9 + -1x)' equal to zero and attempt to solve:
Simplifying
9 + -1x = 0
Solving
9 + -1x = 0
Move all terms containing x to the left, all other terms to the right.
Add '-9' to each side of the equation.
9 + -9 + -1x = 0 + -9
Combine like terms:
9 + -9 = 0
0 + -1x = 0 + -9
-1x = 0 + -9
Combine like terms:
0 + -9 = -9
-1x = -9
Divide each side by '-1'.
x = 9
Simplifying
x = 9
Solution
x = {-5, 9}</span>
