Answer:
ZB= 39°
Step-by-step explanation:
complementary angles are angles that add up to equal 90
equation: 7x + 23 + 5x + 19 = 90
add like terms: 12x + 42 = 90
subtract 42 from both sides: 12x = 48
divide both sides by 12: x = 4
plug in the value of x to the equation for ZB: 5(4) + 19
simplify: ZB= 39°
So, I didn't quite understand your question clearly, but I'll try my best to answer it.
So, the first question is quite simple: Did the runner have a % decrease in his time or an increase.
Well, 7:45 is minor than 5:51. So, his time decreased.
2nd question:
The percent of change. Well, first things first 7:45 has 2 different units, wich are minutes and seconds, I suppose. Same goes for 5:51.
So let's put everything in seconds. multiply both the 7 and 5 for 60(for every minute has 60 seconds.)
That means:
7*60= 420+45 = 465.
5*60=300+51=351.
Now, let's do the math itself:
465 -> 100%
351 -> x%
Is equal to about 75,5%
How much did it decrease then?
(75,5-100)%= 24,5%, approximately
56 + 32 = (8 x 7) + (8 x 4) = 8(7 + 4) (Answer C)
Answer:
The product of x and y would be (8)(-1) = -8. by adding the two equations you get 2x = 16 so x = 8. then y = 7 - x = -1. Therefore xy = -8.
