First convert decimals into fractions where necessary as follows:

0.2 = ²⁄₁₀ = ¹⁄₅

Similarly, 2.5 = ²⁵⁄₁₀ = ⁵⁄₂

We should simplify division part to make expression easier:
^2.4⁄_0.01 = ²⁴⁰⁄₁           (By multiplying both numerator and denominator with 100)

After simplification, we'll get ⁴⁸¹⁄₂

While multiplication operation with decimals, always convert decimals into fractions. So, by converting decimals into fractions, we'll get:

0.01 = ¹⁄₁₀₀

0.025 = ²⁵⁄₁₀₀₀

Thus, in fraction form, question is:
¹⁄₁₀₀ × ²⁵⁄₁₀₀₀

➩ = ²⁵⁄₁₀₀₀₀₀
➩ = 0.00025 Answer!

NOT RECOMMENDED METHOD:     4x² + 8x = 60
➩ 4x² + 8x - 60 = 0

After taking 4 common,
➩ 4(x² + 2x - 15) = 0
➩ x² + 2x - 15 = 0

By factorizing:
➩ x² + 5x - 3x - 15 = 0
➩ x(x + 5) - 3(x + 5) = 0           (Note that sign inside second parenthesis will change upon taking -3 common)

Now, by taking (x + 5) common:
➩ (x + 5) [x(1) - 3(1)] = 0
➩ (x + 5) (x - 3) = 0

➩ Either   x + 5 = 0       or       x - 3 = 0
➩ Either   x = –5       or       x = 3


RECOMMENDED METHOD: Simply plugin each answer choice to the question and check whether the two sides (LHS and RHS) equal?

Don't remember (i.e. Ratta), change the scenario into small scale as follows:

In order to convert into 2 pieces, number of cuts required = 1
Thus, in order to convert into 17, .................. = 16

By multiplying second equation with 2 on both sides to make coefficients of y same:
➩ 4x - 2y = 22 ----------------- (Eq. 1)
And first equation is   3x + 2y = 20 -------- (Eq. 2)

Now, by adding the above two equations:

4x - 2y = 22
3x + 2y = 20
7x           = 42
        ➩   x = 6 Answer!

First simplify expression inside parenthesis. After simplifying first parenthesis, we'll get –6. And after simplifying second parenthesis, we'll get 14.

–6 – 14 = –20

240 centimeter needs to be cut into several equal parts of 12 centimeter each.
First, we need to find number of parts. And then from number of parts, we can determine number of cuts require to do so.

In order to split 240 into 1 centimeter each, we need 240 parts.
In order to split 240 into 2 centimeter each, we need 120 parts.
Thus, in order to split 240 into 12 centimeter each, we need ²⁴⁰⁄₁₂ = 20 parts

Now, 240 parts require 1 cut to split into two parts
Thus, 240 parts require 19 cut to split into 20 parts

Just think if we add the two equations, coefficients of x and y will become 5 each. Thus, we'll get:

5x + 5y = 130
➩ x + y = 26

First, we'll solve division sign:

¹⁴⁄₁₃ ÷ ³⁵⁄₃₉ = ¹⁴⁄₁₃ × ³⁵⁄₃₉

After simplifying this, we'll get:
¹⁴⁄₁₃ × ³⁵⁄₃₉ = ⁶⁄₅

Thus, we have,

⁶⁄₅ + ¹⁵⁄₂ – ²⁵⁄₃

LCM of 5, 2 and 3 is 30, so

⁶⁄₅ + ¹⁵⁄₂ – ²⁵⁄₃ = ^{(6×6 + 15×15 – 25×10)}⁄₃₀

➩ ^{(36 + 225 – 250)}⁄₃₀ = ¹¹⁄₃₀ Answer!

By solving from bottom and taking LCMs, we'll get: ⁵⁄₉