Question

Solve the following system of equations. y + 5x = 30 2y = 5x + 15

Answer 1

Answer: Solve 2y-5x-30 = 0

Tiger recognizes that we have here an equation of a straight line. Such an equation is usually written y=mx+b ("y=mx+c" in the UK).

"y=mx+b" is the formula of a straight line drawn on Cartesian coordinate system in which "y" is the vertical axis and "x" the horizontal axis.

In this formula :

y tells us how far up the line goes

x tells us how far along

m is the Slope or Gradient i.e. how steep the line is

b is the Y-intercept i.e. where the line crosses the Y axis

The X and Y intercepts and the Slope are called the line properties. We shall now graph the line 2y-5x-30 = 0 and calculate its properties

Explanation:

Answer 2

x = 3, y = 15

Explanation:

Given the 2 equations

y + 5x = 30 → (1)

2y = 5x + 15 → (2)

Subtract 5x from both sides in (1)

y = 30 - 5x → (3)

Substitute y = 30 - 5x into (2)

2(30 - 5x) = 5x + 15 ← distribute left side

60 - 10x = 5x + 15 ( subtract 5x from both sides )

60 - 15x = 15 ( subtract 60 from both sides )

- 15x = - 45 ( divide both sides by - 15 )

x = 3

Substitute x = 3 into (3) for corresponding value of y

y = 30 - 5(3) = 30 - 15 = 15

Thus solution is x = 3, y = 15