Help I don't understand !

First convert the equation to slop intercept form:

2x - 7y - 21 = 0

7y = -2x + 21

y = -2/7x + 3

the equation of the perpendicular will always have a slope that is the negative reciprocal of the original slope.

The question says it has the same y-intercept, (0, 3), so the final equation will be y = 7/2x + 3

The attached image is a graph of the two lines. Sure enough, they're perpendicular with the same y-intercept.

cells do need food. in a process known as cellular respiration, cells convert biochemical energy (oxygen as food) from nutrients into adenosine triphosphate (atp), and then release waste products.

hope this .. : d

11.2

step-by-step explanation:

when doing tangent the tangent of the angle is equal to the opposite side from the angle over the adjacent side to the angle.

tan43 = x / 12

move 12 over by multiplying each side by 12

12tan43 = x

x = about 11.2