Solve the system of equations using substitution or graphing. y= -x2 + 4x + 5
y= x + 1
OA) (-1,0) and (6,7)
OB) (-1,0) and (4,5)
C) (1, 2) and (4,5)
D) (1, 2) and (6,7)

Need 50 will mark brainliest answer. find the lengths of all the sides and the measures of the angles.

Asmall business produces and sells balls. the fixed costs are $20 and each ball costs $4.32 to produce. each ball sells for $8.32. write the equations for the total cost, c, and the revenue, r, then use the graphing method to determine how many balls must be sold to break even.

1. according to the internal revenue service, the mean tax refund for the year 2007 was $2,708. assume the standard deviation is $650 and that the amounts refunded follow a normal probability distribution. a. what percent of the refunds are more than $3,000? b. what percent of the refunds are more than $3,000 but less than $4,000? c. what percent of the refunds are less than $2,000?