1. find the sum. (4n2 + 2n + 8) + (5n2 + n + 13)
a. 9n2 + 3n + 21
b. 9n4 + 3n2 + 21
c. 9n2 + 2n + 21
2. find the sum. (2x2 - 5x + 2) + (x2 - 2x + 5)
a. 3x2 - 7x + 7
b. 3x2 - 3x + 7
c. 2x2 + 3x + 7

How many kilograms of a 5% salt solution and how many kilograms of a 15% salt solution must be mixed together to make 45kg of an 8% salt solution?

50 points and will mark brainlest if you were constructing a triangular frame, and you had wood in the length of 4inches, 4 inches, and 7 inches, would it make a triangle? would you be able to create a frame from these pieces of wood? yes or no? = explain your mathematical thinking:

At wind speeds above 1000 centimeters per second (cm/sec), significant sand-moving events begin to occur. wind speeds below 1000 cm/sec deposit sand and wind speeds above 1000 cm/sec move sand to new locations. the cyclic nature of wind and moving sand determines the shape and location of large dunes. at a test site, the prevailing direction of the wind did not change noticeably. however, the velocity did change. fifty-nine wind speed readings gave an average velocity of x = 1075 cm/sec. based on long-term experience, σ can be assumed to be 245 cm/sec. (a) find a 95% confidence interval for the population mean wind speed at this site. (round your answers to the nearest whole number.) lower limit cm/sec upper limit cm/sec