KS2 Primary Maths Age 9-13 - Ratio, Proportion and Algebra: Formulas and Expressions - Explained

The video tutorial addresses a math problem where X and Y are whole numbers less than 10, solving the equation X + 2Y = 20. It highlights common mistakes, such as using numbers 10 or greater, and demonstrates solving the equation with different values of X, starting with X=1, which doesn't work, and then successfully with X=2. The tutorial also presents other valid solutions, emphasizing the importance of adhering to the problem's constraints.

What is the main constraint for the numbers X and Y in the equation X + 2Y = 20?

• X and Y must be even numbers.

• X and Y must be less than 10.

• X and Y must be greater than 10.

• X and Y must be prime numbers.

Why is X = 1 not a valid solution for the equation X + 2Y = 20?

• It results in X being greater than 10.

• It makes Y greater than 10.

• It makes Y a non-whole number.

• It results in a negative value for Y.

If X = 2, what is the value of Y in the equation X + 2Y = 20?

• Y = 10

• Y = 9

• Y = 8

• Y = 11

Which of the following pairs (X, Y) is a valid solution for the equation X + 2Y = 20?

• (X = 3, Y = 8)

• (X = 4, Y = 8)

• (X = 5, Y = 7)

• (X = 6, Y = 5)

What is the accepted solution pair for the equation X + 2Y = 20 as mentioned in the video?

• (X = 4, Y = 9)

• (X = 3, Y = 9)

• (X = 2, Y = 9)

• (X = 1, Y = 9)