Introduction to systems of linear equations

‘If a car is traveling for an hour at a speed $v_{1}$, and then for an hour at a speed $v_{2}$,​ it will cover $120$ kilometers. If it is traveling for a half an hour at a speed $v_{1}$, and then for an hour at a speed $v_{2}$, ​ it will cover $150$ kilometers. Find $v_{1}$ and $v_{2}$.’

‘If a car is traveling for an hour at a speed $v_{1}$, and then for an hour at a speed $v_{2}$, ​it will cover $150$ kilometers. If it is traveling for two hours with the speed $v_{1}$​, and then for an hour with the speed $v_{2}$, ​ it will cover $120$ kilometers. Find $v_{1}$ ​ and $v_{2}$.’

‘If a car is traveling for an hour at a speed $v_{1}$, and then for an hour at a speed $v_{2}$, ​it will cover $150$ kilometers. If it is traveling for a half an hour with the speed $v_{1}$​, and then for an hour with the speed $v_{2}$, ​ it will cover $120$ kilometers. Find $v_{1}$ ​ and $v_{2}$.’

‘If a car is traveling for an hour at a speed $v_{1}$, and then for an hour at a speed $v_{2}$, ​it will cover $150$ kilometers. If it is traveling for an hour with the speed $v_{1}$​, and then for two hours with the speed $v_{2}$,​ it will cover $120$ kilometers. Find $v_{1}$ ​ and $v_{2}$.’ ​