Answer:
wow thats a lot let me write this down
If 30% were perfect, 70% were not perfect. So we know that 70% of the total number of photographs is 210.
p(70/100)=210 multiply both sides by 100
70p=21000 divide both sides by 70
p=300
So there are 300 photographs in all.
Answer:
Step-by-step explanation: to be honest i do not know
First, you need to rewrite the expression into binomial form, so you are working with two terms (as you world with a quadratic):
(x²)²-3(x²)-4=0
Now, you can place the x²s into brackets as the coefficient is now 1:
(x² )(x² )
Next, find out two numbers that add together to give you -3 and multiply to give -4 (these are the leftover integers after removing the x²s). These two numbers are -4 and 1.
Place the -4 and 1 into the brackets:
(x²-4)(x²+1)=0
Notice that the x²-4 is a difference of two squares, so can be further factorised into (x+2)(x-2)
This leaves you with a final factorisation of:
(x+2)(x-2)(x²+1)=0
Now we handle each bracket individually to obtain our four solutions for x:
x+2=0
x=-2
x-2=0
x=2
x²+1=0
x²=1
x=<span>±1</span>
Answer:
D
Step-by-step explanation:
It just is
