Answer:
5 + 9 = 2(4 - 7.5) = No
Explanation:
Add: 5 + 9 = 14
Conversion a decimal number to a fraction: 7.5 = 75/
10
= 15/
2
a) Write down the decimal 7.5 divided by 1: 7.5 = 7.5/
1
b) Multiply both top and bottom by 10 for every number after the decimal point. (For example, if there are two numbers after the decimal point, then use 100, if there are three then use 1000, etc.)
7.5/
1
= 75/
10
Note: 75/
10
is called a decimal fraction.
c) Simplify and reduce the fraction
75/
10
= 15 * 5/
2 * 5
= 15 * 5/
2 * 5
= 15/
2
Subtract: 4 - 7.5 = 4/
1
- 15/
2
= 4 · 2/
1 · 2
- 15/
2
= 8/
2
- 15/
2
= 8 - 15/
2
= -7/
2
For adding, subtracting, and comparing fractions, it is suitable to adjust both fractions to a common (equal, identical) denominator. The common denominator you can calculate as the least common multiple of the both denominators - LCM(1, 2) = 2. In practice, it is enough to find the common denominator (not necessarily the lowest) by multiplying the denominators: 1 × 2 = 2. In the next intermediate step the fraction result cannot be further simplified by canceling.
In words - four minus fifteen halfs = minus seven halfs.
Multiple: 2 * the result of step No. 3 = 2 * (-7/
2
) = 2 · (-7)/
1 · 2
= -14/
2
= -7 · 2/
1 · 2
= -7
Multiply both numerators and denominators. Result fraction keep to lowest possible denominator GCD(-14, 2) = 2.
In words - two multiplied by minus seven halfs = minus seven.
Compare: the result of step No. 1 vs the result of step No. 4 = 14 vs (-7) = No
Thank you...