Answer: d=42
Step-by-step explanation:
Both angles are in a supplementary (straight with 180 degrees) line bisected by an angle, so use the supplementary angle theory
(d+7)+(3d+5)=180
4d+12=180
4d=168
d=42
Answer:
Step-by-step explanation:
Apply the exponent rule 
to a
Apply the exponent rule to b
Apply the exponent rule 
Answer:
(21x+168)cm²
Step-by-step explanation:
If the expression 2 1 (x + 8) represents the area of the model bridge, where 2 1 is the width, in centimeters, and (x + 8) represents the extended length, the expression that is equivalent to 21(x+8) can be gotten by expanding the function. The expansion of the function will give the area of the rectangular model bridge as shown;
21(x+8) = 21x+ 168
The expression equivalent to 21(x+8) is therefore (21x+68)cm²
Note that the the unit of the value and function given is in cm therefore the unit of their equivalent expression will be in cm²
Point B is in the third quadrant
