The Difference of Square: a^2 - b^2 = (a + b)(a - b) Sara did a question as: 2x^2 - 2y^2 = (2x + 2y)(2x - 2y).

What's wrong with Sara's work? How to fix it?

Step-by-step explanation:

Given

Difference of two squares:

Sara Solution to a question:

Required

State what's wrong with Sara's work

How to fix it

In Sara's solution, the coefficient of x and y is 2. Sara's solution is wrong because she included the coefficients of x and y when converting the expression to difference of two squares.

To fix this, the very first thing that needs to done is to factorize the given expression (as follows)

Then the difference of two squares can be applied on the expression in bracket. This gives

- "runner b is moving at a slower rate."

- "the graphs shown are graphs of distance(km) against time(min).

the slopes of this graphs are are given by:

slope = (change in y)/(change in x)

= (change in distance)/(change in time)

this is the formula for finding the speed. so, the slope of these graphs represent the speed of the runner.

taking each division in the graph to represent 1 on both axis:

runner a ⇒ speed = (2-0)/(1-0)

= 2/1

= 2 km/min

runner b ⇒ speed = (3-0)/(3-0)

= 3/3

= 1 km/min

this shows that   runner b is moving at a slower rate."

step-by-step explanation:

to find if any function is an inverse of the other, put the first equation in as x in the next one. then simplify and solve. if at the end you get the statement y = x, then it is an inverse. if you get anything else, it is not.