Remember that exponentioal rule
x^m times x^n=x^(m+n)
therefor
7^4 times 7^-6=7^(4-6)=7^(-2)
remember the other rule
x^-m=1/(x^m) so
7^-2=1/(7^2)=1/49
answe ris A
1.x^2 +6x - 4 = 6x
X^2 + 6x -4 - 6x = 0
X^2 - 4 = 0
By difference of two squares :
X^2 - 4 = 0 can be written as (x-2) (x+2) = 0
(X-2)=0 therefore x= 2
(X+2)=0 therefore x= -2
2. X^2 - 8x = -6x
X^2 -8x + 6x = 0
X^2 - 2x = 0
X(X-2) = 0
X= 0, X= 2
Answer:
<em>The cost of 10 cm and 70 cm are £0.55 and £3.85 respectively.</em>
Step-by-step explanation:
Material for a dress costs £5.50 per meter.
We know that, <u>1 meter = 100 cm</u>.
Suppose, the cost of 10 cm material is 
and the cost of 70 cm material is 
Now, <u>according to the ratio of "cost" to the "length of material"</u> , we will get.......
and
So, the cost of 10 cm material is £0.55 and the cost of 70 cm material is £3.85
Answer:
25
Step-by-step explanation:
144/60 = 2.4
60/2.4 = x
x = 25
The area of a circle is A = πr^2. We let A1 And A2 the areas of the circles and r1 and r2 the radius of each, respectivley.
A1 + A2 = 80π
Substitute the formula for the area,
π(r1)^2 + π (r2)^2 = 80π
From the statement, we know that r2=2(r1).
<span>π(r1)^2 + π (2 x r1)^2 = 80π
</span>We can cancel π, we will have
5 x (r1)^2 = 80
Thus,
r1 = 4 and r2 = 8
