How do you evaluate 4y ^ { 2} + 54y2+5 when y=3y=3?

2 Answers
Mar 4, 2018

4141

Explanation:

"substitute y = 3 into the expression"substitute y = 3 into the expression

rArr(4xxcolor(red)(3)^2)+5(4×32)+5

=(4xx9)+5=36+5=41=(4×9)+5=36+5=41

Mar 4, 2018

= 41 =41

Explanation:

The first thing is to use the knowledge of squaring:

y^2 = y xx y y2=y×y

Hence using "bidmas":

4y^2 + 5 = (4xxyxxy) + 5 4y2+5=(4×y×y)+5

We can just replace yy with 33:

= (4xx3xx3) + 5 =(4×3×3)+5

= (4xx9) +5 =(4×9)+5

= 36 + 5 =36+5

= 41 =41