Answer:
450
(I can't post the answer if it's less than 20 letters so just ignore this I'm trying to fill up)
So legnth is 7 more than 6 times width
l=7+6w
area=10 cm^2
lw=area
subsitute
7+6w for l
(7+6w)(w)=10
7w+6w^2=10
subtract 10 from both sides
6w^2+7w-10=0
factor
multiply 6 and -10
get -60
now find what 2 numbers multiply to get -60 and add to get 7
the answe ris -5 and 12
split up 7w into that
6w^2+7w-10=0
6w^2+12w-5w-10=0
group
(6w^2+12w)+(-5w-10)=0
undistribute factors
(6w)(w+2)+(-5)(w+2)=0
reverse distribute (ab+ac=a(b+c)
(w+2)((6w)+(-5))=0
(w+2)(6w-5)=0
set each to zero
w+2=0
subtract 2
w=-2
false, legnths cannot be negative
6w-5=0
add 5
6w=5
divide both sides by 6
w=5/6
subsitute
l=7+6w
l=7+6(5/6)
l=7+5
l=12
legnth=12 cm
width=5/6 cm
calculate area of wall
20 x 1.5 = 30 square meters
now calculate area of 1 block
12 x 18 =216 square centimeters
convert cm to meters 1 cm^2 = 0.0001m^2
so 216 x 0.0001 = 0.0216 sq meter for 1 block
divide area of wall by area of block
30/0.0216 = 1388.88 so 1389 blocks are required.
The simplified expression is 
Explanation:
The given expression is 
Let us simplify the expression.
Multiplying the numbers in the numerator, we have,
Dividing the term 144 by 3, which results in 48.
Thus, we have,
Applying the fraction rule 
, we get,
Applying the exponent rule 
, we have,
Thus, the simplified expression is
