Answer:
9
Solution:
Write it in an algebraic form (x is your number)
2x-11=7
Now solve
2x=7+11=18
X=18/2=9
Answer:
168 inches are in 14 feet
Step-by-step explanation:
There are 12 inches in a foot. 12 * 14 = 168.
Answer:
400 people
Step-by-step explanation:
15 = 12
500 = x
Cross multiply
15x = 12 × 500
Divide both sides by 15
= 
(* means multiplication if you do not know)
= 100 × 4= 400 people
Answer:
X= 5, -9
Step-by-step explanation:
(X+2)² =49
Expand the bracket,
(X+2) (X+2)= 49
Apply the distributive property;
X(X+2) +2 (X+2) =49
X²+2X+2X+4=49
X²+4X+4=49
Move 49 to the left side of the equation;
X²+4X+4-49=0
X²+4X-45=0
Apply Factorisation method;
Consider the form
a²+bx+c=0
Find two numbers whose sum is equal to b and whose product is equal to c.
Comparing with our equation;
B =4 and C =45
We can use 9 and -5, this is because ;
9+(-5)=4 and 9*(-5)= 45.
Replace X +4X-45=0 with (X-5) (X+9)=0
Therefore;
X-5=0
X+9=0
Moving to the left side of the equation;
Therefore X= 5 and -9
