what is the value of x in the equation 4x + 8y = 40, when y = 0.8? 4.6 8.4 10 12

Explanation:

Step1: Substitute ( y = 0.8 ) into the equation

Substitute ( y = 0.8 ) into ( 4x+8y = 40 ), we get ( 4x+8\times0.8=40 ).

Step2: Simplify the equation

Calculate ( 8\times0.8 = 6.4 ), so the equation becomes ( 4x+6.4 = 40 ).

Step3: Isolate the term with ( x )

Subtract ( 6.4 ) from both sides: ( 4x=40 - 6.4 ). ( 4x=33.6 ).

Step4: Solve for ( x )

Divide both sides by ( 4 ): ( x=\frac{33.6}{4} ). ( x = 8.4 ).

Answer:

B. ( 8.4 )