B. 23
Hope this helps!!!!!!
Hello : the system is :
<span> y= -2x+4 ...(1)
y= x² +4x+13....(2)
x²+4x+13 = -2x+4
x²+6x+9=0
(x+3)² =0
x+3=0
x= -3
subsct in (1) : y=-2(-3)+4 =10</span>
Answer:
Mean age = 1271.27
Step-by-step explanation:
No of children = 77
The age at which children first began to combine words = 16.51 months
Mean age = No of children × age at which children first began to combine words
= 77 × 16.51
= 1271.27
Mean age = 1271.27
The answer is B (Sorry for the bad handwriting.)