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7x-20=3x+4, what is the value of x?

The question is asking you to find the value of x, x represents a number. Therefore, 7x means 7 times a number- this the number we are trying to find out. The first step is to get all the numbers containing ...
RT
Answered by Rebecca T. • Maths tutor
7083 Views

Solve the simultaneous equations: y=3x+2, x^2+y^2=20

y=3x+2 x^2+y^2=20 x^2+(3x+2)^2=20 x^2+(3x+2)(3x+2)=20 x^2+(9x^2+6x+6x+4)=20 x^2+(9x^2+12x+4)=20 10x^2+12x+4=20 10x^2+12x-16=0 5x^2+6x-8=0 (5x-4)(x+2)=0 5x-4=0, x+2=0 x=4/5=0.8, x=-2 y=3x+2, y=3x+2 y=3(0.8)+2...
DC
Answered by Daniela C. • Maths tutor
16013 Views

3x^2 + 7x - 13 = 0. What is x?

By using the quadratic quation, it can be deduced that x = 1.22 or x = -3.55
MS
Answered by Miranda S. • Maths tutor
5858 Views

Differentiate y = (x^2 + 3)^2

We have to use the chain rule here. If we set u to the inside of the bracket, u = x^2 + 3 and differentiating we get du/dx = 2x. Now the original expression becomes y = u^2. Differentiating this with respect...
MH
Answered by Matthew H. • Maths tutor
8354 Views

Simplify the surd sqrt(48)

When simplifying surd expressions we want to look for square numbers that are factors of the number inside the square root. If we list the square numbers (which are numbers that are the result of squaring an...
MH
Answered by Matthew H. • Maths tutor
41483 Views