49x^2 - 9 = 0
As there is no x term, we can pretty much guess we have a situation where we factlrise by something known aa difference of two squares, so to factorise it:
49 = 7^2
9 = 3^2
x^2 = (x)^2
so...
(7x - 3)(7x + 3) = 0
7x - 3 = 0 7x + 3 = 0
x = 3/7 x = -3/7
Answer:
f(-5) = 22
Step-by-step explanation:
All we do is substitute x = -5 into the function.
= -3(-5) + 7
= 15 + 7
= 22
Best of Luck!
Only 20%of earths water is useable
Answer:
5 seconds
Step-by-step explanation:
The ground is 25 eet, so 25=-16t^2+400
-16t^2=-400, 16t^2=400
t^2=25, dividing both sides by 16
t=5 seconds.