Dan wanted to find an equivalent to the expression 3(x + 7) +5. His work is show Step 1: 3(x+ 7) +5= (3x + 7) +5
Step 2: 3(x + 7) + 5 = 3x + ( 7+5)
Step 3: 3(x + 7) + 5 = 3x + 12
In which step, if any, did Dan first make an error?
Step 1
Step 2
© Step 3
Dan did not make any mistakes in his work.

step-by-step explanation:

x^2 -12x + 36 + y^2 = 36

x^2 + y^2 = 12x

r^2 = 12rcos(theta)

r = 12 cos(theta)

7.9m and 4.3°

step-by-step explanation:

let east be +x and north be +y, x = distance * cos θ, y = distance * sin θ  

for 3.5 south, y = -3.5  

for 8.2, x = 8.2 * cos 30 and y = 8.2 * sin 30  

for 15 west, x = -15  

total x = 8.2 * cos 30 – 15 ≈ -7.9  

total y = -3.5 + 8.2 * sin 30 = 0.6  

magnitude = [(8.2 * cos 30 – 15)^2 + 0.6^2)]^0.5  

the magnitude is approximately 7.9 m  

tan θ = y/x = 0.6/-7.9  

the angle is approximately 4.3˚ north of west