(a+b)(a-b)=a^2 - b^2
so
<span>(4x-7)(4x+7) = 16x^2 - 49
answer
</span>16x^2 - 49
Answer:
Step-by-step explanation:
The coefficients of the x terms are {1, 3, -3}, so the discriminant, b^2 - 4ac, is 3^2 - 4(1)(-3), or 9 + 12, or 21. The positive nature of the discriminant tells us that there are two real, unequal roots. Following the quadratic formula, we get:
-3 ± √21
x = -----------------
2
Answer:
7.6m/s
Step-by-step explanation:
Find the time the Olympian swam
Speed=distance/time ⇒⇒Time=distance/speed
Distance=200m , speed= 1.8m/s t= 200/1.8 = 111.11 seconds
Find the speed of the Olympic runner
Distance=200m time = 21.3 sec
s=200/21.3 = 9.4 m/s
Difference in speed= 9.4-1.8= 7.6m/s
