help with math... i beg u?

Question

tell if the problems are prime, or the two numbers that go with them...
please im only in eight grade and i missed half this classs for orhtodonsits

x^2+39x+140
z^2+30z+160
u^2 +77u+360
x^2-98x+2001

Answer 1

I'm not sure what you mean by "prime", but three of them can be factored over the integers:

x² + 39x + 140 = (x + 35)(x + 4)
z² + 30z + 160 cannot be factored over the integers [it can be factored as
(z + 15+sqrt(65))(z + 15-sqrt(65))]
u² + 77u + 360 = (u + 5)(u + 72)
x² - 98x + 2001 = (x - 69)(x - 29)

I found these by using the quadratic formula. If you haven't learned that yet, the only other method I know uses the Rational Root Theorem.

For example, for the first polynomial, the theorem tells us that the integer factors of 140 (positive and negative) are the only possible rational roots of the polynomial. 140 has quite a lot of factors: 1, 2, 4, 5, 7, 10, 14, 20, 28, 35, 70, and 140, and the negatives of these. Because the signs of the coefficient of the x-term and of the constant term are both positive, only the negative factors need to be checked. And of course, as soon as you find one root, say, r, you can divide the polynomial by (x-r) to find the other factor.

A graphing calculator or a computer graphing program can help you find the correct factors.

I would urge you to talk to your teacher about getting help outside of class so that you can catch up.

Answer 2

your question does not make sense. A prime number is a single number (2,3,5,7,11,23...) not an equation