Algebra is a branch of mathematics that deals  with letters  or symbols( called variables ) that stand in for numbers. It allows you to stand in for unknown  quantities in equations and expressions. Essentially,algebra is like a puzzle where you use symbols to represent  what you don't know and then figure out what those symbols stand for.

SUMMARY 

• Variables: these are letters like ( x,y ,z )that represent unknown numbers. 
• Equations : these are statements that show two expressions are equal, often containing variables .
• Solving equations:you use mathematical operations like (addition, multiplication, division, subtraction)  to isolate the variable and find its value . 

For example, in the equation x+5=10 here' x 'is the variable you can solve for' x 'by subtracting 5  by both sides which gives you x =5 

NOW LET'S KNOW HOW ALGEBRA HELPS US 

• Represent relations between things that vary:like the relationship between supply  and price . 
• Use in real life : it is used in budgeting,  cooking (measuring ingredients ) and many  other ways .