When you know the value for letters in an algebraic expression you can substitute these values into the expression and solve it.
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Sometimes you will have to substitute a number into an expression with a square number.
Remember when a number is squared it is multiplied by itself. This is straightforward when you have a positive value.
If \(x~=~10\)
Find \({x}^{2}~+~3\)
How to solve the expression:
\({x}^{2}~+~3\)
\(= {10}^{2}~+~3\)
\(= 10 \times 10~+~3\)
\(=~100~+~3\)
\(=~103\)
When you substitute a negative value for a square number you are multiplying a negative number by a negative number.
Remember that negative times negative equals positive, \(- \times -=+\).
If \(x~=~-10\)
\(= {-10}^{2}~+~3\)
\(= -10 \times -10~+~3\)