To factorise it start with putting the xs in brackets.
(x )(x )
Then you must find 2 numbers which multiply to +81 and sum to -18.
81 is the product of 9×9 or -9×-9.
9+9=+18
-9+-9=-18
So they two numbers must be -9.
So factorised it is (x-9)(x-9) or (x-9)^2
Ok, so 7 5 4
we know that the longest side must be less than the sum of the 2 othe sides
7 is longest
7<5+4
7<9
true
yes it can be (but it's not a right triangle)
Answer:
<u>Answer</u><u>:</u><u> </u><u>4</u><u>x</u><u>²</u><u> </u><u>-</u><u> </u><u>9</u><u>x</u><u> </u><u>+</u><u> </u><u>2</u><u>0</u><u> </u>
Step-by-step explanation:
• General quadratic equation:

• sum of roots → 4 + 5 = 9
• product of roots → 4 × 5 = 20
• substitute:
