Twice the square of a certain whole number added to 3 times the number makes 90.Find the number.

Question

Twice the square of a certain  whole number added to 3 times the number makes 90.Find the number.

asian boy · Answer

15?

Ms. Sue · Answer

15^2 = 225 The number can't be 15.

Nana · Answer

Word problems leading to quadratic equation

Blessing · Answer

Please help me solve this

Art · Answer

It's 6. 2 times 6 squared is 72, 3 times 6 is 18, and 72+18=90. If you don't know algebra, you could just guess and find out what number comes out to 90. If you do, use the quadratic formula. 2x^2+3x=90 x=(-3+/-sqrt((3^2)-4*2*(-90))/(2*2)=(-3+/-sqrt(729))/4=(-3+27)/4 or (-3-27)/4=6 or -7.5, and -7.5 isn't a whole number but 6 is.