Answer:

Step-by-step explanation:
We know that A and B are complementary angles. So, they must add up to 90°. As an equation:

Since we know their equations, substitute:

Solve for x. Combine like terms on the left:

Subtract 9 from both sides:

Divide both sides by 9:

So, the value of x is 9.
We want to find A. So, let's use the equation for A:

Substitute 9 for x:

Add:

So, the measure of A is 17°.
9-t=t+3
Subtract t on both sides
-2t=-6
Divide by -2 to leave the variable by itself
t=3
Answer:
18.02 cm
Step-by-step explanation:
A diagonal makes a rectangle into two right triangles. So if we use the Pythagorean theorem we can find the hypotenuse which is the diagonals.
Remember, because we know the length and width, we know the two sides.
10^2 + 15^2 = c^2
100+225 = c^2
325 = c^2
18.027 ≈ c
The answer would be B.
For these, you plug in 8 where there ia a variable. 2(8)-1=15
Answer:
-0.39mL
Step-by-step explanation:
Let x be the number.
The expression would be: 0.40 + x = 0.01
Apply algebra to the equation to solve for x. You can subtract 0.40 from each side to simplify the expression. Here's what it should look like after applying algebra: x = -0.39
Therefore the answer is -0.39mL