Question

what is the value of y in the equation 5x + 2y = 20, when x = 0.3?
2.5
2.8
9.25
10.75

Explanation:

Step1: Substitute x = 0.3 into the equation

Substitute \( x = 0.3 \) into \( 5x + 2y = 20 \), we get \( 5\times0.3 + 2y = 20 \).

Step2: Simplify the left - hand side

Calculate \( 5\times0.3=1.5 \), so the equation becomes \( 1.5 + 2y = 20 \).

Step3: Isolate the term with y

Subtract 1.5 from both sides of the equation: \( 2y=20 - 1.5 \).
Calculate \( 20 - 1.5 = 18.5 \), so \( 2y = 18.5 \).

Step4: Solve for y

Divide both sides of the equation by 2: \( y=\frac{18.5}{2}=9.25 \).

Answer:

9.25 (the option "9.25")