During a grand prix car race, the tyres on a car are reduced in mass by 3%. if their mass is 388 kg at the end of the race, what was their mass at the start?

Their mass at the start was 400 kg.

Step-by-step explanation:

Given:

The tyres on a car during a grand prix race are reduced in mass by 3%. Their mass is 388 kg at the end of the race.

Now, to find the mass at the start.

Let the mass at the start be .

According to question:

⇒

⇒

⇒

Dividing both sides by 0.97 we get:

⇒

Therefore, their mass at the start was 400 kg.

5x + 3y = - 4

step-by-step explanation:

the equation of a line in standard form is

ax + by = c ( a is a positive integer and b, c are integers )

express the line first of all in slope- intercept form

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

to calculate m use the gradient formula

m = ( y₂ - y₁ ) / ( x₂ - x₁ )

with (x₁, y₁ ) = (7, - 3) and (x₂, y₂ ) = (4, - 8)

m = = -

y = - x + c ← is the partial equation

to find c substitute either of the 2 points into the partial equation

using (4, - 8 ), then

- 8 = - + c ⇒ c = -

y = - x - ← in slope-intercept form

multiply all terms by 3 to eliminate the fractions

3y = - 5x - 4 ( add 5x to both sides )

5x + 3y = - 4 ← in standard form