If 8a+2b+7c=4 what is -7c–

Mathematics

1 answer:

Mandarinka [93]3 years ago

5 0

$8a+2b+7c=4\ \ \ \ |-7c\\\\8a+2b=4-7c\ \ \ \ |-4\\\\8a+2b-4=-7c\\\\\boxed{-7c=8a/-2b-4}$

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A line contains the points (-1, 6), (6, k) and (20, 3). What is the value of k?

AURORKA [14]

Consider, pls, this option:
1. if a required line has a form y=ax+b, then points A(-1;6); B(6;k) and C(20;3) belong to it.
2. According to the item 1 it is possible to make up the system of equations for A and C:
$\left \{ {{-a+b=6} \atop {20a+b=3}} \right \ \left \{ {{a=- \frac{1}{7} } \atop {b= \frac{41}{7} }} \right.$
Knowing, that a=-1/7 and b=41/7, it is possible to write the equation of required line:
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Answer: 5.

7 0

3 years ago

Slope is 3/7,and (4,9) is on the line

TiliK225 [7]

Answer:

$y-9=\frac{3}{7}(x-4)$

$y=\frac{3}{7}x+\frac{51}{7}$

Step-by-step explanation:

To write the equation of the line using a slope and a point, use the point-slope formula $y-y_1 = m(x-x_1)$ . Here m is 3/7. And the point $(x_1,y_1)$ is (4,9). Substitute the values and simplify.