Class 8 Math Chapter 3 Test

Order of Operations

• To solve $5(7 + 3)$, first calculate the sum inside the parentheses: $7 + 3 = 10$.
• Then multiply the result by 5: $5 \times 10 = 50$.
• Therefore, the value of $5(7 + 3)$ is 50.

Combining Like Terms

• To simplify $2x + 3y - 5x$, identify terms with the same variables.
• Combine the $x$ terms: $2x - 5x = -3x$.
• Keep the $y$ term unchanged.
• The simplified expression is $-3x + 3y$.

Right-Angled Triangles

• The Pythagorean theorem states that in a right-angled triangle, the square of the hypotenuse (the longest side) is equal to the sum of the squares of the other two sides.
• In this case, the longest side is 13 cm.
• Check if $13^2 = 5^2 + 12^2$.
• Calculate the squares: $169 = 25 + 144$.
• The equation holds true, therefore the triangle is a right-angled triangle.

Adding Fractions

• To add fractions, they must have the same denominator (bottom number).
• Find the least common multiple of 3 and 4, which is 12.
• Convert $\frac{1}{3}$ to $\frac{4}{12}$ and $\frac{1}{4}$ to $\frac{3}{12}$.
• Add the numerators: $\frac{4}{12} + \frac{3}{12} = \frac{7}{12}$.
• Therefore, the value of $\frac{1}{3} + \frac{1}{4}$ is $\frac{7}{12}$.

Test your knowledge of Chapter 3 math concepts with this quiz. Solve expressions, determine triangle types, and simplify fractions.