The answer to your question is 215
3x+4y=12
9x-2y=15
we will use elimination
multiply 3x+4y=12 by -3
-9x-12y=-36
9x-2y=15
_________ add
-14y=-21
÷-14 both sides
y=1.5
find x
3x+4 (1.5)=12
3x+6=12
-6 both sides
3x=6
÷3 both sides
x=2
x=2
y=1.5
Option C: 90° is the value of x.
Explanation:
The given expression is
for 
We need to solve the expression.
Thus, we have,

Subtracting both sides by 4, we have,

Adding both sides by 8 sin x, we get,

Dividing both sides by 10, we have,

Taking
on both sides of the equation, we get,


Thus, the value of x is 90°
Hence, Option C is the correct answer.
Answer:
x = 30 in
Step-by-step explanation:
length of rectangle is (2/3)x + 10; width is (1/3)x + 5;
perimeter is 90 in; find x:
P = 90 in = 2(2/3)x + 2(10) + 2(1/3)x + 2(5), or
90 in = (6/3)x + 30 in
Solving for x, we get (2)x = 60 in, or x = 30 in