That's the answer
-You have to multiply each side by 2
-And then move the constant to the right
And then calculate
26-18=x
X=-8
Answer:
x = -2
y = 5
Step-by-step explanation:
Given two equations
1. 7x + 10y = 36
2. y = 2x + 9
Substitute 2x + 9 for y in equation 1.
We have
7x + 10y = 36
7x + 10(2x + 9) = 36
Distribute 10 into (2x + 9)
We have
7x + 10 x 2x + 10 x 9 = 36
7x + 20x + 90 = 36
27x + 90 = 36
Subtract 90 from both sides to eliminate 90 on the left side
27x + 90 - 90 = 36 - 90
27x = -54
Divide both sides by 27 to isolate x
27x/27 = -54/27
x = -2
Now substitute -2 into either equation to get y
Using equation 2, we have
y = 2x + 9
= 2 x -2 + 9
= -4 + 9
= 5
x = -2
y = 5
Check
7(-2) + 10(5) = 36
<span>0.5x - 0.1 = -2.9
When you multiply each side of an equation by the same number,
you don't change the equation or its solution. If you want to get rid
of the decimals, you could multiply each side by 10. Then the
equation is
5x - 1 = -29
You should be able to solve that without help.
But I'm about to take your points, so here's
how to solve that equation:
</span><span><span>5x - 1 = -29
Add 1 to each side: 5x = -28
Divide each side by 5 : x = -28 / 5
Simplify the solution: x = -5 and 4/5 .
Again ... this is the same solution as the original equation
if we hadn't gotten rid of the decimals.
</span></span>
Answer:
The 90% confidence interval for the mean time required by all college graduates is between 5.36 years and 5.44 years.
Step-by-step explanation:
We have that to find our
level, that is the subtraction of 1 by the confidence interval divided by 2. So:
Now, we have to find z in the Ztable as such z has a pvalue of
.
So it is z with a pvalue of
, so
Now, find the margin of error M as such
In which
is the standard deviation of the population and n is the size of the sample.
The lower end of the interval is the sample mean subtracted by M. So it is 5.4 - 0.04 = 5.36 years.
The upper end of the interval is the sample mean added to M. So it is 5.4 + 0.04 = 5.44 years.
The 90% confidence interval for the mean time required by all college graduates is between 5.36 years and 5.44 years.