Top answers

The equation 5x^2 + px + q = 0, where p and q are constants, has roots t and t+4. Show that p^2 = 20q + 400.

We know that if we have a polinomial of the form ax^2 + bx + c = 0, then:sum of the roots = -b/a and product of the roots = c/a Therefore: t + (t + 4) = -p/5 and t(t + 4) = q/5 Therefore: 2t + 4 = -p/5 so t ...
AB
Answered by Alexandra B. • Maths tutor
5160 Views

Solve the simultaneous equations: 3x+5y=19, 4x-2y=-18

For all simultaneous equations it is useful to number each one to keep your working clear and concise. In order to solve this we need to eliminate one of the variables (x or y) by manipulating the equations....
BW
Answered by Ben W. • Maths tutor
10067 Views

If 5x + 3y = 27 and 6x - 2y = 10, find x and y

5x + 3y = 27 (1)6x - 2y = 10 (2)Rearrange (1) to make x the subject.Subtracting - 3y from both sides gives5x = 27 - 3yDivide both sides by 5 givesx = (27 - 3y)/5Substitute (1) into (2) gives6(27 - 3y)/5 - 2y...
TA
Answered by Thomas A. • Maths tutor
3997 Views

How do I plot a graph of y=x^3-9x?

To begin with we see that y=x 3 -9x is a positive cubic function, and therefore we know its general shape.The first step is to find the x interecepts. We do this by setting y=0 and solving the resulting equa...
TD
Answered by Tutor127548 D. • Maths tutor
9091 Views

Nine-thousand five-hundred and forty-two people attend a pop concert. Round this number to the nearest hundred.

Answer: nine-thousand five-hundred (9,500) There are 9 thousands, 5 hundreds, four tens and 2 units. We need to round the hundreds and the answer we have in 5 hundreds. Because of there being 5 hundreds we n...
AW
Answered by Alexandra W. • Maths tutor
4033 Views