0.1d+0.25(d+8)=4.1 — step-by-step solution

Let's solve in

ℝ

0.1 d + 0.25 \cdot (d + 8) = 4.1

ⓘ Expand by multiplying each term inside the parentheses:

0.25 \cdot (d + 8)

0.25 d + 2

0.1 d + 0.25 d + 2 = 4.1

ⓘ Like terms are grouped by adding their coefficients:

0.1 d + 0.25 d

0.35 d

0.35 d + 2 = 4.1

ⓘ We subtract

2

from both sides

0.35 d = 4.1 - 2

ⓘ Start from

4.1

and move back

2

on the number line:

4.1 - 2

2.1

0.35 d = 2.1

ⓘ Both sides are divided by

0.35

d = \frac{2.1}{0.35}

ⓘ The numerator and the denominator are multiplied by

100

to remove the decimal point, then divided by

35

, their greatest common divisor:

\frac{2.1}{0.35}

\frac{2.1 \cdot 100}{0.35 \cdot 100}

\frac{210}{35}

6

▶Solution obtained:

d = 6