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2 years ago

Solve the system of equations by the substitution method: 4x-y = 35 7x + 6y = 38

Mathematics

1 answer:

Leokris [45]2 years ago

8 0

Answer:

x=8 and y=−3

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What is the radius of a circumference 56.5

Bas_tet [7]

8.992254284692088 is the radius I believe

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3 years ago

For which interval does this quadratic inequality hold true?

adoni [48]

Answer:

Step-by-step explanation:

x²-4x-12≤0

x²-6x+2x-12≤0

x(x-6)+2(x-6)≤0

(x-6)(x+2)≤0

x=6,-2

∴ value of x lies between -2 & 6

3 0

11 months ago

Two boats leave a port at the same time, one going north and the other traveling south. The northbound boat travels 18 mph fast

shutvik [7]

Answer:

10 hours

Step-by-step explanation:

Two boats leave a port at the same time, one going north and the other traveling south.

<u>Southbound boat rate</u> = 40 mph

The northbound boat travels 18 mph faster than the southbound boat.

<u>Northbound boat rate</u> = 40 + 18 = 58 mph

Two boats rate = 40 + 58 = 98 mph (this means they are apart 98 km after one hour)

Total distance = 980 miles

Total rate = 98 mph

Time $=980:98=10$ hours

3 0

3 years ago

Find the inverse of ????−7 −2

Masja [62]

Answer:

$A^{-1}=\begin{bmatrix}1 & 2\\ -4 & -7\end{bmatrix}$

Step-by-step explanation:

$A=\begin{bmatrix}-7 & -2\\ 4 & 1\end{bmatrix}$

$det\ A=-7\times 1-(-2)\times 4\\\Rightarrow det\ A=1$

$A^{-1}=\frac{1}{det\ A}\begin{bmatrix}1 & 2\\ -4 & -7\end{bmatrix}\\\Rightarrow A^{-1}=\frac{1}{1}\begin{bmatrix}1 & 2\\ -4 & -7\end{bmatrix}\\\Rightarrow A^{-1}=\begin{bmatrix}1 & 2\\ -4 & -7\end{bmatrix}$

$\therefore A^{-1}=\begin{bmatrix}1 & 2\\ -4 & -7\end{bmatrix}$

$A.A^{-1}=\begin{bmatrix}-7 & -2\\ 4 & 1\end{bmatrix}\times \begin{bmatrix}1 & 2\\ -4 & -7\end{bmatrix}\\\Rightarrow A.A^{-1}=\begin{pmatrix}\left(-7\right)\cdot \:1+\left(-2\right)\left(-4\right)&\left(-7\right)\cdot \:2+\left(-2\right)\left(-7\right)\\ 4\cdot \:1+1\cdot \left(-4\right)&4\cdot \:2+1\cdot \left(-7\right)\end{pmatrix}\\\Rightarrow A.A^{-1}=\begin{pmatrix}1&0\\ 0&1\end{pmatrix}$

Hence, confirmed

6 0

3 years ago

7 less than three fifths of b is a

Citrus2011 [14]

It would be 3/5b-7=y?

4 0

3 years ago

Read 2 more answers