SaiBook.us Algebra

Example

Title: Find the value of the variable in the equation

Grade: 7-a Lesson: S4-L2

Explanation: The best way to understand algebra is by looking at some examples. Take turns and read each example for easy understanding.

Examples:

1. Solve \$a/(3 + 1) = (a + 2)/5\$.

Step 1a

Given algebraic equation is that,
\$a/(3 + 1) = (a + 2)/5\$.

$1a$

Explanation: Here we have the algebraic equation \$a/(3 + 1) = (a + 2)/5\$.

Step 1b

Cross multiply the equation to make it easier to solve the equation.

$1b$

Explanation: Cross multiply the equation to make it easier to solve the algebraic equation,

\$a/(3 + 1) = (a + 2)/5\$

i.e, multiply \$5\$ with \$a\$ & \$(a +2)\$ with \$(3 +1)\$

\$=> 5(a) = {(a + 2)(3 + 1)}\$

Step 1c

Perform multiplication between the algebraic expressions in the above equation.

$1c$

Explanation: Multiply the algebraic expressions \${(a + 2)(3 + 1)}\$.

\$=> 5a = {(a + 2)(3 + 1)}\$
\$=> 5a = {3a + 6 + a + 2}\$
\$=> 5a = 4a + 8\$

We get, \$ 5a = 4a + 8\$

Step 1d

Now sovle the equation for a.

$1d$

Explanation: \$ 5a = 4a + 8\$

Move all the varible terms to one side of the equation and constant terms to another side of the equation. \$=> 5a - 4a = 8\$

Now perform operations among the terms.
\$=> 5a - 4a = 8\$
\$=> 1a = 8\$
\$=> a = 8\$.