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3 years ago

Solving a system of linear equations using the substitution method. 5x+4y=-26 5-x=-6y

2 answers:

5 0

Solve for x in 2nd equation
times -1 both sides
x-5=6y
add 5
x=6y+5

sub

5(6y+5)+4y=-26
30y+25+4y=-26
34y+25=-26
minus 25 both sides
34y=-51
divide both sides by 34
y=-3/2
sub back

x=6y+5
x=6(-3/2)+5
x=-18/2+5
x=-9+5
x=-4

(-4,-3/2) is solution

Naddik [55]3 years ago

5 0

We write x in terms of y in order to substitute using the second equation
-x=-6y-5
x= 6y+5

We substitute what we got above in the first equation
5(6y+5)+4y=-26

We solve for y
30y+25+4y=-26
34y+25=-26
34y=-51
y=-51/34

Then we plug what we got for y back in our first equation in order to get the value of x as well

x=6(-51/34)+5
x=-4

So the solutions are:
x=-4
y=-1.5

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Bart used place value and the distributive property to rewrite the expression 6(412). His work is shown below. 6(412) = 6(400 +

egoroff_w [7]

Bart should;

Multiply 6(400), 6(10), and 6(2) ⇒ 2nd

Multiply each addend by 6 ⇒ 4th

Find the sum of (2400 + 60 + 12) ⇒ 5th

Step-by-step explanation:

Let us revise the distributive property

a(b + c) = ab + ac
a(b + c + d) = ab + ac + ad

Bart used place value and the distributive property to rewrite the

expression 6(412)

His work is shown 6(412) = 6(400 + 10 + 2)

We need to know what Bart should do to find the product

∵ 6(412) = 6(400 + 10 + 2)

- Multiply each number in the bracket by 6 in the right hand side

∴ 6(400 + 10 + 2) = (6)(400) + (6)(10) + 6(2)

∴ 6(400 + 10 + 2) = 2400 + 60 + 12

∴ He should to multiply each addend by 6 and then find the sum of

(2400 + 60 + 12)

Bart should;

Multiply 6(400), 6(10), and 6(2)

Multiply each addend by 6

Find the sum of (2400 + 60 + 12)

Learn more:

You can learn more about the place value in brainly.com/question/120752

#LearnwithBrainly

5 0

3 years ago

Read 2 more answers

In analyzing the city and highway fuel efficiencies of many cars and trucks, the mean difference in fuel efficiencies for the 60

Olegator [25]

Answer:

$7.38-1.96\frac{2.51}{\sqrt{601}}=7.18$

$7.38+1.96\frac{2.51}{\sqrt{601}}=7.58$

For this case the confidence interval is given by :

$7.18 \leq \mu \leq 7.58$

Step-by-step explanation:

Data provided

$\bar X=7.38$ represent the sample mean for the fuel efficiencies

$\mu$ population mean

s=2.51 represent the sample standard deviation

n=601 represent the sample size

Confidence interval

The formula for the confidence interval of the true mean is given by:

$\bar X \pm t_{\alpha/2}\frac{s}{\sqrt{n}}$ (1)

The degrees of freedom for this case is given by:

$df=n-1=601-1=600$

The Confidence level for this case is 0.95 or 95%, and the significance level $\alpha=0.05$ and $\alpha/2 =0.025$ and the critical value is given by $t_{\alpha/2}=1.96$