x^-10x+21=0 quadratic equation?

Question

A)-7 and - 3
B)-21 and1
C)5 and 2
D)7 and 3

Answer 1

This an eqwuation of degree 2. You can use Bhaskara. But the solutions are 2 numbers whose sum is 10 and whose product is 21, so we readily see the solutions are 7 and 3.

Answer 2

X^ - 10X + 21=0
First factor the equation to get:
(X-7)(X-3)=0
If X is 7 you get:
(7-7)(7-3)=0
0*4=0
0=0

If X is 3 you get:
(3-7)(3-3)=0
-4*0=0
0=0

So the answer is D. 7 or 3

Answer 3

d) 7 and 3

Answer 4

You want two numbers that multiply to 21 and add to -10
These numbers are -7 and -3 (-7*-3 = 21 and -7+-3 =-10)

So (x-7)(x-3) = 0
Therefore x = 7 or x = 3
Answer D

Answer 5

answer's D
x^2-7x-3x+21=0
x(x-7)-3(x-7)=0
(x-7)=0 (x-3)=0
x=7 x=3
for future reference, here's a basic definition of quadratic equations: quadratic equations are those where the highest power of a variable is 2.
plus, i think you forgot to mention x's power (you left it at x^)