Question

A straight line y = mx + c is parallel to y = 3x +2

and passes through the point (1, 2). Find the values
of m and c.​

Answer 1

m = 3 and c = -1

Explanation:

1) A straight line y = mx + c is parallel to y = 3x +2

so : same slope m = 3......... y= 3x+c

2) passes through the point (1, 2) : when x=1 y = 2

2 = 3(1)+c c = -1

an equation is : y = 3x - 1

Answer 2

m = 3 and c = - 1

Explanation:

The equation of a line in slope- intercept form is

y = mx + c ( m is the slope and c the y- intercept )

y = 3x + 2 ← is in slope- intercept form

with m = 3

• Parallel lines have equal slopes, thus

y = 3x + c ← is the partial equation of the parallel line

To find c substitute (1, 2) into the partial equation

2 = 3 + c ⇒ c = 2 - 3 = - 1

y = 3x - 1 ← equation of parallel line

with m = 3 and c = - 1