Substitute 2x+1 where y is in the equation:
9x-2(2x+1)=8
Then distribute the -2(2x+1)
9x-4x+2=8
Then combine like terms (the x)
5x+2=8
Then do -2 on both side of the equation sign
5x+2=8
- 2 -2
Then you'd get
5x=6
Then divide 5 on both sides
X= 1.2
Answer: $80.44
Step-by-step explanation:
First of all, find 20% of 78.86, which is approximately 15.77.
Then, add it to the cost of the meal.
Finally, discount 15% of 94.63, which is approximately $14.19, and then subtract it from $94.63, and there's your answer.
Remark
You are dealing with a right angle triangle. You can use one of Sin(x) Cos(x) or Tan(x). Since the Hypotenuse is involved and since you are given the adjacent side, Cos(71) is what you will need.
Solution
H = BC
Cos(x) = adjactent / hypotenuse
Cos(71) = 6.3 / H Multiply both sides by H
H * Cos(71) = 6.3 Divide by Cos(71)
H = 6.3 / cos(71) Cos(71) = 0.32557
H = 6.3 / 0.32557 Divide
H = BC = 19.351 Answer
Sandra lays 3.75 tiles in one hour
