Answer:
x = 
Step-by-step explanation:
Given
-
=
+ 
Multiply through by 12 ( the LCM of 2, 3 and 4 ) to clear the fractions
18x - 6 = 4 + 3x ( subtract 3x from both sides )
15x - 6 = 4 ( add 6 to both sides )
15x = 10 ( divide both sides by 15 )
x =
= 
Answer:
m∠Q = 121°
m∠R = 58°
m∠S = 123°
m∠T = 58°
Step-by-step explanation:
The sum of the interior angles of a quadrilateral = 360°
Create an expression for the sum of all the angles and equate it to 360, then solve for x:
∠Q + ∠T + ∠S + ∠R = 360
⇒ 2x + 5 + x + 2x + 7 + x = 360
⇒ 6x + 12 = 360
⇒ 6x = 360 - 12 = 348
⇒ x = 348 ÷ 6 = 58
So now we know that x = 58, we can calculate all the angles:
m∠Q = 2x + 5 = (2 x 58) + 5 = 121°
m∠R = x = 58°
m∠S = 2x + 7 = (2 x 58) + 7 = 123°
m∠T = x = 58°
Let the number of text messages be represented by X.
Then the total cost of David's cell phone adds up to

Since the total cost of David's phone equals $91.40, we get the following equation.

Subtract 50 on both sides

Divide both sides by 0.45

Therefore David has send 92 text messages.
Step-by-step explanation:
I think I did the right process but the answer didn't match.