Question

"Solve the system of equations: y = 4x - 3 and y = -3x^2 + 3x +11"

Do I add them up or what?

Answer 1

They are both equal to y and therefore both equal to eachother.
4x -3 = -3x^2 + 3x + 11
0 = -3x^2 -1x + 14

Solve using quadratic formula or factorising and simplifying.
If you need help on quadratic formula or factorising I can also help :)

Answer 2

I got x = 3 +/- 13/ -6. Is that correct? Do you always use the quadratic formula when something equals 0? And if two equations are equal to y they always equal each other? That's so cool! Thank you so so much!

Answer 3

If two equations equal y they can be plotted onto the same graph. Where they intercept is the "solution" (x,y) to your simultaneous equation. Basicly by solving the equation you found where the two lines meet, if they don't intersect, there is no solution. You will learn about this later in maths I assume.

You don't always use the quadratic formula. If you can factrose easily you don't need to use it, if you can't the quadratic formula can be used. Just remember when using the quadratic formula your equation must equal 0 :)

Answer 4

Okay, that makes total sense. Thank you for explaining so thoroughly. :)

Answer 5

Not a prob. Anything else I can help you with?

Answer 6

If you could, that would be great! "if f(x) = 2x - 8 then find f (-x)"

Answer 7

Would it just be -2x - 8? Or something different and more complicated?

Answer 8

Nope. perfectly right.

Answer 9

Awesome, thank you.