Answer:
C. 3, -7
Step-by-step explanation:
x^2 +4x-21 =0
Factor
What 2 numbers multiply to -21 and add to 4
7*-3 = -21
7-3 = 4
(x+7) (x-3) =0
Using the zero product property
x+7 =0 x-3=0
x+7-7=0-7 x-3+3=0+3
x = -7 x=3
Answer:
9.64ft
Step-by-step explanation:
Since the diagram tends to form...a right angled triangle....;
with PR = 17ft...,PQ = 14ft
then to calculate the length of QR
we use the pythagoras theorem...which is only applicable to right angled triangles
PR^2 = PQ^2 + QR^2
(17)^2 = (14)^2 + QR^2
where we make QR the subject of formula;
QR^2 = (17)^2 - (14)^2
QR = square root of( 289 - 196)
QR = square root of( 93)
;Therefore the length of QR = 9.64ft
When you simplify the square root of a number, you are looking for factors of the number that are perfect squares that you can remove from under the radical. For example sq root of 8... it's not a perfect square but factors of 8 include 2 x 4... 4 is a perfect square so we can take it out of the radical by taking it's square root. Now you are left with 2* sq root of 2.
For sq root of 48
48 = 12 x 4
12 = 3x4 so we can say 48 = 3x4x4
so... sq root 48 = sq root 3x4x4
we have two 4's under the radical. Sq root x^2 = x so sq root 4^2 is 4
Pull it out from the radical and we are left with 4 * sq root 3
BajajajajajajajajajajajjajajajjjajajahHh
