Question

Please help me with math !!

the diagram shows two parallel lines OP and RQ. Straight line PQ is parallel to the y-axis and O is the origin.

a) Find the equation of the straight line PQ.
b) Find the equation of the straight line RQ.
c) Find the x-intercept of the straight line RQ.​

Answer 1

• a) x = 4
• b) y = 1.25x + 15
• c) (-12, 0)

Explanation:

a) PQ is parallel to the y-axis and contains point (4, 5).

It means its equation is:

• x = 4

b) RQ is parallel to OP.

Parallel lines have equal slopes.

Find the slope of OP:

• m = 5/4 = 1.25

RQ has slope of 1.25 and passes through (- 8, 5).

Find its equation using point-slope form:

• y - 5 = 1.25(x - (-8))
• y - 5 = 1.25x + 10
• y = 1.25x + 15

c) The x-intercept is determined at y = 0:

• 0 = 1.25x + 15
• 1.25x = - 15
• x = - 15/1.15
• x = - 12