Top answers

If x^2 = 16, why isn't the answer just x = 4?

You're right that x = 4 is a solution to the equation - but the problem is it's not the only solution, x = -4 also works.You have to be careful not to take a shortcut by simply taking the square root of both...
LD
Answered by Laurie D. • Maths tutor
17921 Views

solve 2x^2+4x-7=0

Notice that this is a quadratic. First you should try factorisation, then if unsuccessful try completing the square (or the quadratic formula). In this example, factorisation is not possible (I can this furt...
KW
Answered by Katie W. • Maths tutor
8606 Views

Solve the simultaneous equations: y=x/2 + 2 and 2y+3x=12

Label the equations (1): y=x/2 + 2 and (2): 2y+3x=12. Firstly, multiply equation (1)by 2, this will give you (1a): 2y=x+4, then, substitute (1a) into (2). This gives you (x+4)+3x=12. Therefore, 4x+4=12. 4x=1...
JB
Answered by Joseph B. • Maths tutor
6704 Views

Solve the equation x^2-9x+20=0

First, we need to factorise the equation on the left hand side, this can be done by finding two numbers that add together to make the 'b' coefficient (-9) and multiply to make the 'c' coefficient (20). This ...
JB
Answered by Joseph B. • Maths tutor
30449 Views

Solve (4-2x)/(x+1)=x

To solve this equation, we need to collect all of the x^2 terms and the x terms together. To do this we should start by getting rid of the fraction on the left-hand side by multiplying both sides by the deno...
EK
Answered by Emily K. • Maths tutor
10170 Views