Solve 0.21*4*10^7=4.2*10^3*m*20

$$0.21 \times 4 \times 10 ^ { 7 } = 4.2 \times 10 ^ { 3 } \times m \times 20$$

Solve for m

$$m=100$$

Steps for Solving Linear Equation

Multiply 0.21 and 4 to get 0.84.

$$0.84\times 10^{7}=4.2\times 10^{3}m\times 20$$

Calculate 10 to the power of 7 and get 10000000.

$$0.84\times 10000000=4.2\times 10^{3}m\times 20$$

Multiply 0.84 and 10000000 to get 8400000.

$$8400000=4.2\times 10^{3}m\times 20$$

Calculate 10 to the power of 3 and get 1000.

$$8400000=4.2\times 1000m\times 20$$

Multiply 4.2 and 1000 to get 4200.

$$8400000=4200m\times 20$$

Multiply 4200 and 20 to get 84000.

$$8400000=84000m$$

Swap sides so that all variable terms are on the left hand side.

$$84000m=8400000$$

Divide both sides by 84000.

$$m=\frac{8400000}{84000}$$

Divide 8400000 by 84000 to get 100.

$$m=100$$