What is the value of the expression below when x=4? 2x2+x-5

Mathematics

2 answers:

nlexa [21]3 years ago

5 0

Answer:

Step-by-step explanation:

(2×2)+x-5

=4+x-5

=4+(4)-5

=8-5

Zielflug [23.3K]3 years ago

3 0

Answer:

2x2+x-5

using x=4

(2×2)+4-5

4+(-1)

4-1=3

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Find the value of r so the line that passes through (-5,2) and (3,r) has a slope of -1/2

soldier1979 [14.2K]

The value of r so the line that passes through (-5,2) and (3,r) has a slope of -1/2 is -2

Solution:

Given that line is passing through point (-5, 2) and (3, r)

Slope of the line is $\frac{-1}{2}$

Need to determine value of r.

Slope of a line passing through point $\left(x_{1}, y_{1}\right) \text { and }\left(x_{2}, y_{2}\right)$ is given by following formula:

$\text { Slope } m=\frac{y_{2}-y_{1}}{x_{2}-x_{1}}$ --- eqn 1

$\text { In our case } x_{1}=-5, y_{1}=2, x_{2}=3, y_{2}=\mathrm{r} \text { and } m=-\frac{1}{2}$

On substituting the given value in (1) we get

$\begin{array}{l}{-\frac{1}{2}=\frac{r-2}{3-(-5)}} \\\\ {\text { Solving the above expression to get value of } r} \\\\ {=>-\frac{1}{2}=\frac{r-2}{3+5}} \\\\ {=>-8=\frac{r-2}{3+5}} \\\\ {=>-8=2(r-2)} \\\\ {=>-8=2 r-4} \\\\ {=>2 r=-8+4} \\\\ {=>2 r=-4} \\\\ {=>r=\frac{-4}{2}=-2}\end{array}$