21.3 is the correct answer.
Answer:
None of the answers provided are equivalent
Step-by-step explanation:
To solve it would be best to simplify each of the expressions you have listed by combining like terms all the x^2 terms have been bolded, the x terms italicized, and the constant terms are underlined
(<em>4x</em> <u>+ 1.2</u>) + (2x ^ 2 <em>- 6x</em> <u>+ 5</u>) = 2x ^ 2 <em>- 6x</em> <u>+ 6.2</u>
(x ^ 2 <em>- 5x</em> +<u> 13</u>) + (x ^ 2 <em>+ 3x </em><u>- 6</u>) = 2x^2 <em>-2x </em><u>+7</u>
(4x ^ 2<em> - 6x</em> <u>+ 11</u>) + (2x ^ 2<em> - 4x</em><u><em> </em></u><u>+ 4</u>) = 6x^2 -<em>10x </em><u>+15</u>
(5x ^ 2 <em>- 8x</em> <u>+ 120</u>) + (- 3x ^ 2 <em>+ 10x</em> <u>- 13</u>) = 2x^2 <em>+ 2x</em> <u>+ 107</u>
One side is -4.
It can also be x + 4.
Turn 16 + 8x + x^2 into standard form —> x^2 + 8x + 16
Note: standard form is ax^2 + bx + c
Use the “foil” method to factor.
(x + 4)(x + 4)
x=-4
The idea being, you multiply top and bottom by a value that will raise the radicand in the denominator, to the same as the root, thus coming out of the root, so, let's do so
Answer:
4 by 10
Step-by-step explanation:
4 times 10 is 40 (length times width)
4+4+10+20=28