The triangle has a base of 4 and a height of 2.
Answer:





Step-by-step explanation:
Solving (a):
7x - 19 and 3x + 14 are interior angles.
So:

Collect like terms



7x - 19 and 5y - 2 are equal angles --- corresponding angles
So:

Make 5y the subject

5y = 7x -17
Make y the subject

Substitute 



Solving (b):
The triangle is right-angled.
So:

Collect Like Terms



Answer:
x= 30
Step-by-step explanation:
3x + 50 = 140
3x = 140 -50
3x = 90
x = 90/3
x = 30
Answer:
He must survey 123 adults.
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of
, and a confidence level of
, we have the following confidence interval of proportions.
In which
z is the z-score that has a p-value of
.
The margin of error is:

Assume that a recent survey suggests that about 87% of adults have heard of the brand.
This means that 
90% confidence level
So
, z is the value of Z that has a p-value of
, so
.
How many adults must he survey in order to be 90% confident that his estimate is within five percentage points of the true population percentage?
This is n for which M = 0.05. So






Rounding up:
He must survey 123 adults.
How to solve your question
Your question is
4
+
1
=
2
−
5
4x+1=2x-5
4x+1=2x−5
Solve
1
Subtract
1
1
1
from both sides of the equation
2
Simplify
3
Subtract
2
2x
2x
from both sides of the equation
4
Simplify
5
Divide both sides of the equation by the same term
6
Simplify
Solution
=
−
3