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3 years ago

How to solve these questions using substitution

Mathematics

2 answers:

Tanzania [10]3 years ago

7 0

Please see the pics, I'd solved in it. and I'm so sorry for cuttings.

ikadub [295]3 years ago

3 0

For question 6
Make x for first one subject of formulae
then it becomes
x=-2y
Substitution means replace your answer in the second part
since x=-2y
3(-2y) +4y = 4
-6y+4y=4
-2y=4
y= 4/-2
y=-2

Now to find x,replace the answer for y in one in the equation
so i replace y=-2 in the first part
x=-2y
x= -2(-2)
x=4
Therefore x=4 and y=-2
To check your answer replace x and y by the values you got and check if you get same answer.

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What expression is equivalent to ^3 square root of 2y^3 times 7 square root of 18y

Mumz [18]

Answer:

$\sqrt[3]{2y^3} * 7\sqrt{18y} = 21(y^{\frac{3}{2}})(2^{\frac{5}{6}})$

Step-by-step explanation:

The question is poorly formatted.

Given

$\sqrt[3]{2y^3} * 7\sqrt{18y}$

Required

Derive an equivalent expression

$\sqrt[3]{2y^3} * 7\sqrt{18y}$

Express 18 as 9 * 2

$\sqrt[3]{2y^3} * 7\sqrt{9 * 2y}$

Split the expression as follows:

$\sqrt[3]{2y^3} * 7\sqrt{9} * \sqrt{2y}$

Take positive square root of 9

$\sqrt[3]{2y^3} * 7*3 * \sqrt{2y}$

$\sqrt[3]{2y^3} * 21 * \sqrt{2y}$

$21*\sqrt[3]{2y^3} * \sqrt{2y}$

The cube root can be rewritten to give:

$21*\sqrt[3]{2}*\sqrt[3]{y^3} * \sqrt{2y}$

$\sqrt[3]{y^3} = y^{3*\frac{1}{3}} = y$

So, we have:

$21*\sqrt[3]{2} * y * \sqrt{2y}$

Rewrite as:

$21y *\sqrt[3]{2} * \sqrt{2y}$

Split $\sqrt{2y$

$21y *\sqrt[3]{2} * \sqrt{2} * \sqrt{y}$

Collect Like Terms

$21y*\sqrt{y} *\sqrt[3]{2} * \sqrt{2}$

Represent in index form

$21y*y^{\frac{1}{2}} *2^\frac{1}{3} *2^\frac{1}{2}$

Apply law of indices

$21*y^{1+\frac{1}{2}} *2^{\frac{1}{3} +\frac{1}{2} }$

$21*y^{\frac{2+1}{2}} *2^{\frac{2+3}{6}}$

$21*y^{\frac{3}{2}} *2^{\frac{5}{6}}$

$21(y^{\frac{3}{2}})(2^{\frac{5}{6}})$

Hence:

$\sqrt[3]{2y^3} * 7\sqrt{18y} = 21(y^{\frac{3}{2}})(2^{\frac{5}{6}})$

6 0

3 years ago

Type the correct answer in each box. Use numerals instead of words. If necessary, use / for the fraction bar(s). Consider the eq

wlad13 [49]

The value of x in terms of b is x = $\frac{-3}{b}$ . Therefore the value of x when b = 3 is x = $\frac{-3}{3}$ = -1.

We can find both answers by rearranging the equation to get "x =", and then substituting in 3 for b:

-2(bx - 5) = 16

-2bx + 10 = 16

- 10

-2bx = 6

÷ -2

bx = -3

÷ b

x = -3/b, which is the answer to the first part.

To get the second answer, we just substitute b = 3 into this equation and we get:

x = -3/b = -3/3 = -1

I hope this helps!

4 0

3 years ago

BRAINLIST ADDED?ANSWER THIS QUESTION I WILL UPVOTE YOUR ANSWER!!✔:)

Sidana [21]

Answer:

-10 4/64, -.3125, 1/16, 10 51/80, 10 45/48

Step-by-step explanation:

negatives, the larger the number the smaller it is, opposite for positives. 10 45/48 is closer to 11 than 10 51/80

5 0

3 years ago

Read 2 more answers

Max has x dollars. Keisha has four more dollars than Max.

Dimas [21]

Max has X, and as Keisha has four more,
Keisha is 4+x

The total amount is x+x+4
2x+4

8 0

4 years ago

Read 2 more answers

12w + 40 /3 = -6 What is the value of 'w'?

Lisa [10]

12w + 13¹/₃ = -6
 - 13¹/₃ - 13¹/₃
 12w = -19¹/₃
 12 12
 w = -1¹¹/₁₈

3 0

3 years ago