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3 years ago

Steps to solve 3 (x -5) + 7 x = 65

Mathematics

2 answers:

Novay_Z [31]3 years ago

8 0

Answer:

x = 8

Step-by-step explanation:

3(x-5)+6x = 3x-15+7x

3x-15+7x = 65

10x = 80

x = 8

yanalaym [24]3 years ago

3 0

To solve this, you need to isolate/get the variable "x" by itself in the equation:

3(x - 5) + 7x = 65 Distribute 3 into (x - 5)

(3)x + (3)(-5) + 7x = 65

3x - 15 + 7x = 65 Combine like terms(terms that have the same variable and power/exponent), or combine 3x and 7x

10x - 15 = 65 Add 15 on both sides

10x - 15 + 15 = 65 + 15

10x = 80 Divide 10 on both sides to get "x" by itself

$\frac{10x}{10} =\frac{80}{10}$

x = 8

PROOF

3(x - 5) + 7x = 65 Substitute/plug in 8 into "x" since x = 8

3(8 - 5) + 7(8) = 65

3(3) + 56 = 65

9 + 56 = 65

65 = 65

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Please help: linear algebra problem. (Linear combinations)

DochEvi [55]

Answer:

$\left[\begin{array}{ccc}5&7\\5&-8\\3&-9\end{array}\right] \left[\begin{array}{ccc}c\\d\end{array}\right] =\left[\begin{array}{ccc}-16\\3\\-15\end{array}\right]$

This tells us that:

$A=\left[\begin{array}{ccc}5&7\\5&-8\\3&-9\end{array}\right]$

$b=\left[\begin{array}{ccc}-16\\3\\-15\end{array}\right]$

Step-by-step explanation:

So we are saying we have scalars, c and d, such that:

$c\left[\begin{array}{ccc}5\\5\\ 3\end{array}\right]+d\left[\begin{array}{ccc}7\\-8\\-9\end{array}\right]=\left[\begin{array}{ccc}-16\\3\\-15\end{array}\right]$ .

So we want to find a way to express this as:

Ax=b where x is the scalar vector, $\left[\begin{array}{ccc}c\\d\end{array}\right]$ .

So we can write this as:

$\left[\begin{array}{ccc}5&7\\5&-8\\3&-9\end{array}\right] \left[\begin{array}{ccc}c\\d\end{array}\right] =\left[\begin{array}{ccc}-16\\3\\-15\end{array}\right]$

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3 years ago

Sam bought a pair of socks for 2.95 and a tie for 7.50 . He gave the cashier a twenty dollar bill. How much change should Sam re

oksian1 [2.3K]

7.5+2.95=10.45
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3 years ago

WHAT THE HECC IS THIS

anyanavicka [17]

Answer:

h(x)

Step-by-step explanation: