Concept
Speed is the distance divide by time.
[tex]\begin{gathered} \text{Speed = }\frac{dis\tan ce}{\text{time}} \\ \end{gathered}[/tex][tex]\begin{gathered} x\text{ - y = }\frac{2100}{6} \\ x\text{ - y = 350 ----------------------- 1} \\ x\text{ + y = }\frac{2100}{4} \\ x\text{ + y = 525 -----------------------2} \end{gathered}[/tex]Next, solve the two systems of equations to find the value of x and y.
From equation 1, make y subject of the formula and substitute in equation 2.
x - y = 350
x - 350 = y
Substitute, y = x - 350 in the equation 2.
x + x - 350 = 525
collect like terms
x + x = 525 + 350
2x = 875
Divide 2 on both side to get:
x = 875/2
x = 437.5
Final answer
The speed of the plane with no wind = 437.5
