Question

Select the statement that is true. Answer Choices The sum of 0.12x2+0.3⎯⎯⎯ and 1.5x2−0.75 is 1.62x2+0.416 . -0.45x2+0.9 subtracted from 2.5x2−7.32 is -2.95x2+8.22 . The difference of 18.94x−0.4⎯⎯⎯ and -10.2x+4.5 is 8.74x−4.94⎯⎯⎯ . The product of 0.6⎯⎯⎯x+3.4 and -6x+5.7 is -4x2−16.6x+19.38 .

Answer 1

The operations given will be evaluated as follows:
1]
(0.12x^2+0.3)+(1.5x^2-0.75)
=(0.12x^2+1.5x^2)+(0.3+0.75)
=1.62x+1.05


2]
(2.5x^2-7.32)-(-0.45x^2+0.9)
(2.5x^2+0.45x^2)+(-7.32-0.9)
2.95x^2-8.22

3](18.94x-0.4)-(-10.2x+4.5)
=(18.94x+10.2x)+(-0.4-4.5)
=29.14x-4.9

4] (x+3.4)(-6x+5.7)
=x(-6x+5.7)+3.4(-6x+5.7)
=-6x^2+5.7x-20.4x+19.38
=-6x^2-14.7x+19.38