Search our library of Maths questions

Top answers

Maths

All levels

For all values of x, f(x) = (x + 1)^2 and g(x) = 2(x-1). Show that gf(x) = 2x(x + 2).

f(x)=(x+1)^2g(x)=2(x-1)
gf(x)=2([(x+1^2)]-1) =2([(x+1)(x+1)]-1) =2([x^2+2x+1]-1) =2(x^2+2x) =2x(x+2)

Answered by Quamar Q. • Maths tutor

2651 Views

How to solve the simultaneous equations: 3x+5y=19 and 4x+6y=22

First find a shared factor between the x's or the y's. Both 5 and 6 are a factor of 30. So 30/5 is 6 therefore we multiply the whole of equation 1 by 6 to get 18x+30y=114. Then 30/6 =5 so we multiply the ...

Answered by Rachel K. • Maths tutor

2754 Views

Simplify this algebraic fraction: 2(x+8) + 2(x+6) / x^2 - 49

Let's start with the numerator. According to BIDMAS we first expand the brackets: 2x+16+2x+12 Now add the like terms: 4x+28We can now take 4 out as a factor: 4(x+7)Now looking at the denominator we can re...

Answered by Priti B. • Maths tutor

2416 Views

In a triangle ABC where angle CAB = 90 and angle ABC = 40 and the hypotenuse = 20cm, what is the length CA? Then find the total perimeter of the triangle.

Use SOH CAH TOA to determine which trigonometric function to useTo calculate CA Sine should be usedWe then get an answer of 12.86cm for CAWe can then either use Cosine or pythagorus to calculate AB
F...

Answered by Jack D. • Maths tutor

2487 Views

Show that the lines y=3x+7 and 2y-6x=8 are parallel (not using a graphical method).

The standard form of a straight line is y = mx + c, where y and x are variables that depend on each other, m is the gradient and c is the y-axis intercept. An important fact for this question is that para...

Answered by Matt B. • Maths tutor

3443 Views