Solve 3.5^2=1.4^2+2.8^2-2*1.4^2*{2.8}^2*x

$${ 3.5 }^{ 2 } = { 1.4 }^{ 2 } + { 2.8 }^{ 2 } -2 \times { 1.4 }^{ 2 } \times { 2.8 }^{ 2 } \times x$$

Solve for x

$$x=-\frac{125}{1568}\approx -0.079719388$$

Steps for Solving Linear Equation

Calculate 3.5 to the power of 2 and get 12.25.

$$12.25=1.4^{2}+2.8^{2}-2\times 1.4^{2}\times 2.8^{2}x$$

Calculate 1.4 to the power of 2 and get 1.96.

$$12.25=1.96+2.8^{2}-2\times 1.4^{2}\times 2.8^{2}x$$

Calculate 2.8 to the power of 2 and get 7.84.

$$12.25=1.96+7.84-2\times 1.4^{2}\times 2.8^{2}x$$

Add 1.96 and 7.84 to get 9.8.

$$12.25=9.8-2\times 1.4^{2}\times 2.8^{2}x$$

Calculate 1.4 to the power of 2 and get 1.96.

$$12.25=9.8-2\times 1.96\times 2.8^{2}x$$

Multiply 2 and 1.96 to get 3.92.

$$12.25=9.8-3.92\times 2.8^{2}x$$

Calculate 2.8 to the power of 2 and get 7.84.

$$12.25=9.8-3.92\times 7.84x$$

Multiply 3.92 and 7.84 to get 30.7328.

$$12.25=9.8-30.7328x$$

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

$$9.8-30.7328x=12.25$$

Subtract 9.8 from both sides.

$$-30.7328x=12.25-9.8$$

Subtract 9.8 from 12.25 to get 2.45.

$$-30.7328x=2.45$$

Divide both sides by -30.7328.

$$x=\frac{2.45}{-30.7328}$$

Expand \frac{2.45}{-30.7328} by multiplying both numerator and the denominator by 10000.

$$x=\frac{24500}{-307328}$$

Reduce the fraction \frac{24500}{-307328} to lowest terms by extracting and canceling out 196.

$$x=-\frac{125}{1568}$$