Solve 1.4^2=2.5^2+2.6^2-2*1.4*2.6(0.5c)

$$1.4 ^ { 2 } = 2.5 ^ { 2 } + 2.6 ^ { 2 } - 2 \times 1.4 \times 2.6 ( 0.5 c )$$

Solve for c

$$c = \frac{85}{28} = 3\frac{1}{28} \approx 3.035714286$$

Steps for Solving Linear Equation

Calculate 1.4 to the power of 2 and get 1.96.

$$1.96=2.5^{2}+2.6^{2}-2\times 1.4\times 2.6\times 0.5c$$

Calculate 2.5 to the power of 2 and get 6.25.

$$1.96=6.25+2.6^{2}-2\times 1.4\times 2.6\times 0.5c$$

Calculate 2.6 to the power of 2 and get 6.76.

$$1.96=6.25+6.76-2\times 1.4\times 2.6\times 0.5c$$

Add 6.25 and 6.76 to get 13.01.

$$1.96=13.01-2\times 1.4\times 2.6\times 0.5c$$

Multiply 2 and 1.4 to get 2.8.

$$1.96=13.01-2.8\times 2.6\times 0.5c$$

Multiply 2.8 and 2.6 to get 7.28.

$$1.96=13.01-7.28\times 0.5c$$

Multiply 7.28 and 0.5 to get 3.64.

$$1.96=13.01-3.64c$$

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

$$13.01-3.64c=1.96$$

Subtract 13.01 from both sides.

$$-3.64c=1.96-13.01$$

Subtract 13.01 from 1.96 to get -11.05.

$$-3.64c=-11.05$$

Divide both sides by -3.64.

$$c=\frac{-11.05}{-3.64}$$

Expand \frac{-11.05}{-3.64} by multiplying both numerator and the denominator by 100.

$$c=\frac{-1105}{-364}$$

Reduce the fraction \frac{-1105}{-364} to lowest terms by extracting and canceling out -13.

$$c=\frac{85}{28}$$